Chapter 3 Basic Instrumentation for Nuclear Technology

1 Accelerators

2 Detectors

3 Reactors

Outline of experiment

bull1048708 get particles (eg protons hellip)bull1048708 accelerate thembull1048708 throw them against each otherbull1048708 observe and record what happensbull1048708 analyse and interpret the data

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Naturersquos Particle Accelerators

bull Naturally occurring radioactive sourcesndash Up to 5 MeV Alpharsquos (helium nuclei)ndash Up to 3 MeV Beta particles (electrons)

bull Natural sources are difficult and limitedndash Chemical processing purity messy and expensive ndash Low intensityndash Poor geometryndash Uncontrolled energies usually very broad

Examples from the nature ndash electrostatic discharge α- and β-decays cosmic rays

ldquoStart the ball rollinghelliprdquo1927 Lord Rutherford requested a ldquocopious supplyrdquo of projectiles more energetic than natural alpha and beta particles At the opening of the resulting High Tension Laboratory Rutherford went on to reiterate the goal

What we require is an apparatus to give us a potentialof the order of 10 million volts which can be safely

accommodated in a reasonably sized room and operated by a few kilowatts of power We require too an exhausted tube capable of withstanding this voltagehellip I see no reason why such a requirement cannot be made practical

5

Why studybull The construction design and operation of

particle accelerators uses knowledge from different branches of physics electromagnetism high frequency electronics solid states physics optics vacuum technology cryogenics

bull Learning about particle accelerator is a good opportunity to learn about many different physical phenomenon

Why

They have wide ranging applications well beyond

physics health life science materials and even

archaeology

7

Early accelerators1870 Discovery of the cathode rays by William Crookes

- Charged rays - Propagation from the Cathode to the anode

A Crookes tube in which the Cathode

rays are deflected by a magnetic field

1896 JJ Thomson shows that the cathode rays are made

of ldquoparticlesrdquo and measure the chargemass ratio

These particles are called ldquoelectronsrdquo

Images source Wikipedia

8

Bremsstrahlung

bull When a charged beam hits an object X-rays are emitted This is used to produce X-rays in hospitals but it is also a source of hazardous radiations in accelerators

bull Bremsstrahlung is similar to synchrotron radiation that will be discussed later today

A charged particle emits radiation when it is accelerated

An electron that Coulomb scatters on a heavy nucleus will change

direction =gt acceleration

Bremsstrahlung braking radiation is the name of the radiation

emitted when a charged particle scatters on a heavy nucleus

Image source

httpwwwndt-edorgEducationResources

9

Improved resolutionbull In quantum mechanics the wavelength of an object is

related to its energy by

The reach better resolutions the energy of the probe

must be increased

The energy of the electrons in Cathodic ray tubes is

limited by the electrostatic generators available

In the 1930s several generators where invented to

produce high electric fields

Ion source

acceleration steering analyzer

vacuum

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

12

Particle sources

bull How particles are first producedbull How to extract particles with the right

propertiesbull What are the limitations of the sourcesbull The quality of the source is very important If

the particles emitted by the source do not have the right properties it will be very difficult andor expensive to rectify it later

Beams of nanoamperes to hundreds of amperes

Very thin to very broad beams (μm2 to m2)

Negative to highly charged state

e to protein molecule

14

Emission of electronThermionic effect

(image source wikipedia)

When a metal is heated more electrons

can populate high energy levels

Above a certain threshold they

electrons can break their bound and be

emitted

This is thermionic emission

f=eminusEkBT

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Naturersquos Particle Accelerators

bull Naturally occurring radioactive sourcesndash Up to 5 MeV Alpharsquos (helium nuclei)ndash Up to 3 MeV Beta particles (electrons)

bull Natural sources are difficult and limitedndash Chemical processing purity messy and expensive ndash Low intensityndash Poor geometryndash Uncontrolled energies usually very broad

Examples from the nature ndash electrostatic discharge α- and β-decays cosmic rays

ldquoStart the ball rollinghelliprdquo1927 Lord Rutherford requested a ldquocopious supplyrdquo of projectiles more energetic than natural alpha and beta particles At the opening of the resulting High Tension Laboratory Rutherford went on to reiterate the goal

What we require is an apparatus to give us a potentialof the order of 10 million volts which can be safely

accommodated in a reasonably sized room and operated by a few kilowatts of power We require too an exhausted tube capable of withstanding this voltagehellip I see no reason why such a requirement cannot be made practical

5

Why studybull The construction design and operation of

particle accelerators uses knowledge from different branches of physics electromagnetism high frequency electronics solid states physics optics vacuum technology cryogenics

bull Learning about particle accelerator is a good opportunity to learn about many different physical phenomenon

Why

They have wide ranging applications well beyond

physics health life science materials and even

archaeology

7

Early accelerators1870 Discovery of the cathode rays by William Crookes

- Charged rays - Propagation from the Cathode to the anode

A Crookes tube in which the Cathode

rays are deflected by a magnetic field

1896 JJ Thomson shows that the cathode rays are made

of ldquoparticlesrdquo and measure the chargemass ratio

These particles are called ldquoelectronsrdquo

Images source Wikipedia

8

Bremsstrahlung

bull When a charged beam hits an object X-rays are emitted This is used to produce X-rays in hospitals but it is also a source of hazardous radiations in accelerators

bull Bremsstrahlung is similar to synchrotron radiation that will be discussed later today

A charged particle emits radiation when it is accelerated

An electron that Coulomb scatters on a heavy nucleus will change

direction =gt acceleration

Bremsstrahlung braking radiation is the name of the radiation

emitted when a charged particle scatters on a heavy nucleus

Image source

httpwwwndt-edorgEducationResources

9

Improved resolutionbull In quantum mechanics the wavelength of an object is

related to its energy by

The reach better resolutions the energy of the probe

must be increased

The energy of the electrons in Cathodic ray tubes is

limited by the electrostatic generators available

In the 1930s several generators where invented to

produce high electric fields

Ion source

acceleration steering analyzer

vacuum

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

12

Particle sources

bull How particles are first producedbull How to extract particles with the right

propertiesbull What are the limitations of the sourcesbull The quality of the source is very important If

the particles emitted by the source do not have the right properties it will be very difficult andor expensive to rectify it later

Beams of nanoamperes to hundreds of amperes

Very thin to very broad beams (μm2 to m2)

Negative to highly charged state

e to protein molecule

14

Emission of electronThermionic effect

(image source wikipedia)

When a metal is heated more electrons

can populate high energy levels

Above a certain threshold they

electrons can break their bound and be

emitted

This is thermionic emission

f=eminusEkBT

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Naturersquos Particle Accelerators

bull Naturally occurring radioactive sourcesndash Up to 5 MeV Alpharsquos (helium nuclei)ndash Up to 3 MeV Beta particles (electrons)

bull Natural sources are difficult and limitedndash Chemical processing purity messy and expensive ndash Low intensityndash Poor geometryndash Uncontrolled energies usually very broad

Examples from the nature ndash electrostatic discharge α- and β-decays cosmic rays

ldquoStart the ball rollinghelliprdquo1927 Lord Rutherford requested a ldquocopious supplyrdquo of projectiles more energetic than natural alpha and beta particles At the opening of the resulting High Tension Laboratory Rutherford went on to reiterate the goal

What we require is an apparatus to give us a potentialof the order of 10 million volts which can be safely

accommodated in a reasonably sized room and operated by a few kilowatts of power We require too an exhausted tube capable of withstanding this voltagehellip I see no reason why such a requirement cannot be made practical

5

Why studybull The construction design and operation of

particle accelerators uses knowledge from different branches of physics electromagnetism high frequency electronics solid states physics optics vacuum technology cryogenics

bull Learning about particle accelerator is a good opportunity to learn about many different physical phenomenon

Why

They have wide ranging applications well beyond

physics health life science materials and even

archaeology

7

Early accelerators1870 Discovery of the cathode rays by William Crookes

- Charged rays - Propagation from the Cathode to the anode

A Crookes tube in which the Cathode

rays are deflected by a magnetic field

1896 JJ Thomson shows that the cathode rays are made

of ldquoparticlesrdquo and measure the chargemass ratio

These particles are called ldquoelectronsrdquo

Images source Wikipedia

8

Bremsstrahlung

bull When a charged beam hits an object X-rays are emitted This is used to produce X-rays in hospitals but it is also a source of hazardous radiations in accelerators

bull Bremsstrahlung is similar to synchrotron radiation that will be discussed later today

A charged particle emits radiation when it is accelerated

An electron that Coulomb scatters on a heavy nucleus will change

direction =gt acceleration

Bremsstrahlung braking radiation is the name of the radiation

emitted when a charged particle scatters on a heavy nucleus

Image source

httpwwwndt-edorgEducationResources

9

Improved resolutionbull In quantum mechanics the wavelength of an object is

related to its energy by

The reach better resolutions the energy of the probe

must be increased

The energy of the electrons in Cathodic ray tubes is

limited by the electrostatic generators available

In the 1930s several generators where invented to

produce high electric fields

Ion source

acceleration steering analyzer

vacuum

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

12

Particle sources

bull How particles are first producedbull How to extract particles with the right

propertiesbull What are the limitations of the sourcesbull The quality of the source is very important If

the particles emitted by the source do not have the right properties it will be very difficult andor expensive to rectify it later

Beams of nanoamperes to hundreds of amperes

Very thin to very broad beams (μm2 to m2)

Negative to highly charged state

e to protein molecule

14

Emission of electronThermionic effect

(image source wikipedia)

When a metal is heated more electrons

can populate high energy levels

Above a certain threshold they

electrons can break their bound and be

emitted

This is thermionic emission

f=eminusEkBT

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

ldquoStart the ball rollinghelliprdquo1927 Lord Rutherford requested a ldquocopious supplyrdquo of projectiles more energetic than natural alpha and beta particles At the opening of the resulting High Tension Laboratory Rutherford went on to reiterate the goal

What we require is an apparatus to give us a potentialof the order of 10 million volts which can be safely

accommodated in a reasonably sized room and operated by a few kilowatts of power We require too an exhausted tube capable of withstanding this voltagehellip I see no reason why such a requirement cannot be made practical

5

Why studybull The construction design and operation of

particle accelerators uses knowledge from different branches of physics electromagnetism high frequency electronics solid states physics optics vacuum technology cryogenics

bull Learning about particle accelerator is a good opportunity to learn about many different physical phenomenon

Why

They have wide ranging applications well beyond

physics health life science materials and even

archaeology

7

Early accelerators1870 Discovery of the cathode rays by William Crookes

- Charged rays - Propagation from the Cathode to the anode

A Crookes tube in which the Cathode

rays are deflected by a magnetic field

1896 JJ Thomson shows that the cathode rays are made

of ldquoparticlesrdquo and measure the chargemass ratio

These particles are called ldquoelectronsrdquo

Images source Wikipedia

8

Bremsstrahlung

bull When a charged beam hits an object X-rays are emitted This is used to produce X-rays in hospitals but it is also a source of hazardous radiations in accelerators

bull Bremsstrahlung is similar to synchrotron radiation that will be discussed later today

A charged particle emits radiation when it is accelerated

An electron that Coulomb scatters on a heavy nucleus will change

direction =gt acceleration

Bremsstrahlung braking radiation is the name of the radiation

emitted when a charged particle scatters on a heavy nucleus

Image source

httpwwwndt-edorgEducationResources

9

Improved resolutionbull In quantum mechanics the wavelength of an object is

related to its energy by

The reach better resolutions the energy of the probe

must be increased

The energy of the electrons in Cathodic ray tubes is

limited by the electrostatic generators available

In the 1930s several generators where invented to

produce high electric fields

Ion source

acceleration steering analyzer

vacuum

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

12

Particle sources

bull How particles are first producedbull How to extract particles with the right

propertiesbull What are the limitations of the sourcesbull The quality of the source is very important If

the particles emitted by the source do not have the right properties it will be very difficult andor expensive to rectify it later

Beams of nanoamperes to hundreds of amperes

Very thin to very broad beams (μm2 to m2)

Negative to highly charged state

e to protein molecule

14

Emission of electronThermionic effect

(image source wikipedia)

When a metal is heated more electrons

can populate high energy levels

Above a certain threshold they

electrons can break their bound and be

emitted

This is thermionic emission

f=eminusEkBT

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

5

Why studybull The construction design and operation of

particle accelerators uses knowledge from different branches of physics electromagnetism high frequency electronics solid states physics optics vacuum technology cryogenics

bull Learning about particle accelerator is a good opportunity to learn about many different physical phenomenon

Why

They have wide ranging applications well beyond

physics health life science materials and even

archaeology

7

Early accelerators1870 Discovery of the cathode rays by William Crookes

- Charged rays - Propagation from the Cathode to the anode

A Crookes tube in which the Cathode

rays are deflected by a magnetic field

1896 JJ Thomson shows that the cathode rays are made

of ldquoparticlesrdquo and measure the chargemass ratio

These particles are called ldquoelectronsrdquo

Images source Wikipedia

8

Bremsstrahlung

bull When a charged beam hits an object X-rays are emitted This is used to produce X-rays in hospitals but it is also a source of hazardous radiations in accelerators

bull Bremsstrahlung is similar to synchrotron radiation that will be discussed later today

A charged particle emits radiation when it is accelerated

An electron that Coulomb scatters on a heavy nucleus will change

direction =gt acceleration

Bremsstrahlung braking radiation is the name of the radiation

emitted when a charged particle scatters on a heavy nucleus

Image source

httpwwwndt-edorgEducationResources

9

Improved resolutionbull In quantum mechanics the wavelength of an object is

related to its energy by

The reach better resolutions the energy of the probe

must be increased

The energy of the electrons in Cathodic ray tubes is

limited by the electrostatic generators available

In the 1930s several generators where invented to

produce high electric fields

Ion source

acceleration steering analyzer

vacuum

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

12

Particle sources

bull How particles are first producedbull How to extract particles with the right

propertiesbull What are the limitations of the sourcesbull The quality of the source is very important If

the particles emitted by the source do not have the right properties it will be very difficult andor expensive to rectify it later

Beams of nanoamperes to hundreds of amperes

Very thin to very broad beams (μm2 to m2)

Negative to highly charged state

e to protein molecule

14

Emission of electronThermionic effect

(image source wikipedia)

When a metal is heated more electrons

can populate high energy levels

Above a certain threshold they

electrons can break their bound and be

emitted

This is thermionic emission

f=eminusEkBT

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Why

They have wide ranging applications well beyond

physics health life science materials and even

archaeology

7

Early accelerators1870 Discovery of the cathode rays by William Crookes

- Charged rays - Propagation from the Cathode to the anode

A Crookes tube in which the Cathode

rays are deflected by a magnetic field

1896 JJ Thomson shows that the cathode rays are made

of ldquoparticlesrdquo and measure the chargemass ratio

These particles are called ldquoelectronsrdquo

Images source Wikipedia

8

Bremsstrahlung

bull When a charged beam hits an object X-rays are emitted This is used to produce X-rays in hospitals but it is also a source of hazardous radiations in accelerators

bull Bremsstrahlung is similar to synchrotron radiation that will be discussed later today

A charged particle emits radiation when it is accelerated

An electron that Coulomb scatters on a heavy nucleus will change

direction =gt acceleration

Bremsstrahlung braking radiation is the name of the radiation

emitted when a charged particle scatters on a heavy nucleus

Image source

httpwwwndt-edorgEducationResources

9

Improved resolutionbull In quantum mechanics the wavelength of an object is

related to its energy by

The reach better resolutions the energy of the probe

must be increased

The energy of the electrons in Cathodic ray tubes is

limited by the electrostatic generators available

In the 1930s several generators where invented to

produce high electric fields

Ion source

acceleration steering analyzer

vacuum

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

12

Particle sources

bull How particles are first producedbull How to extract particles with the right

propertiesbull What are the limitations of the sourcesbull The quality of the source is very important If

the particles emitted by the source do not have the right properties it will be very difficult andor expensive to rectify it later

Beams of nanoamperes to hundreds of amperes

Very thin to very broad beams (μm2 to m2)

Negative to highly charged state

e to protein molecule

14

Emission of electronThermionic effect

(image source wikipedia)

When a metal is heated more electrons

can populate high energy levels

Above a certain threshold they

electrons can break their bound and be

emitted

This is thermionic emission

f=eminusEkBT

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

7

Early accelerators1870 Discovery of the cathode rays by William Crookes

- Charged rays - Propagation from the Cathode to the anode

A Crookes tube in which the Cathode

rays are deflected by a magnetic field

1896 JJ Thomson shows that the cathode rays are made

of ldquoparticlesrdquo and measure the chargemass ratio

These particles are called ldquoelectronsrdquo

Images source Wikipedia

8

Bremsstrahlung

bull When a charged beam hits an object X-rays are emitted This is used to produce X-rays in hospitals but it is also a source of hazardous radiations in accelerators

bull Bremsstrahlung is similar to synchrotron radiation that will be discussed later today

A charged particle emits radiation when it is accelerated

An electron that Coulomb scatters on a heavy nucleus will change

direction =gt acceleration

Bremsstrahlung braking radiation is the name of the radiation

emitted when a charged particle scatters on a heavy nucleus

Image source

httpwwwndt-edorgEducationResources

9

Improved resolutionbull In quantum mechanics the wavelength of an object is

related to its energy by

The reach better resolutions the energy of the probe

must be increased

The energy of the electrons in Cathodic ray tubes is

limited by the electrostatic generators available

In the 1930s several generators where invented to

produce high electric fields

Ion source

acceleration steering analyzer

vacuum

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

12

Particle sources

bull How particles are first producedbull How to extract particles with the right

propertiesbull What are the limitations of the sourcesbull The quality of the source is very important If

the particles emitted by the source do not have the right properties it will be very difficult andor expensive to rectify it later

Beams of nanoamperes to hundreds of amperes

Very thin to very broad beams (μm2 to m2)

Negative to highly charged state

e to protein molecule

14

Emission of electronThermionic effect

(image source wikipedia)

When a metal is heated more electrons

can populate high energy levels

Above a certain threshold they

electrons can break their bound and be

emitted

This is thermionic emission

f=eminusEkBT

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

8

Bremsstrahlung

bull When a charged beam hits an object X-rays are emitted This is used to produce X-rays in hospitals but it is also a source of hazardous radiations in accelerators

bull Bremsstrahlung is similar to synchrotron radiation that will be discussed later today

A charged particle emits radiation when it is accelerated

An electron that Coulomb scatters on a heavy nucleus will change

direction =gt acceleration

Bremsstrahlung braking radiation is the name of the radiation

emitted when a charged particle scatters on a heavy nucleus

Image source

httpwwwndt-edorgEducationResources

9

Improved resolutionbull In quantum mechanics the wavelength of an object is

related to its energy by

The reach better resolutions the energy of the probe

must be increased

The energy of the electrons in Cathodic ray tubes is

limited by the electrostatic generators available

In the 1930s several generators where invented to

produce high electric fields

Ion source

acceleration steering analyzer

vacuum

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

12

Particle sources

bull How particles are first producedbull How to extract particles with the right

propertiesbull What are the limitations of the sourcesbull The quality of the source is very important If

the particles emitted by the source do not have the right properties it will be very difficult andor expensive to rectify it later

Beams of nanoamperes to hundreds of amperes

Very thin to very broad beams (μm2 to m2)

Negative to highly charged state

e to protein molecule

14

Emission of electronThermionic effect

(image source wikipedia)

When a metal is heated more electrons

can populate high energy levels

Above a certain threshold they

electrons can break their bound and be

emitted

This is thermionic emission

f=eminusEkBT

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

9

Improved resolutionbull In quantum mechanics the wavelength of an object is

related to its energy by

The reach better resolutions the energy of the probe

must be increased

The energy of the electrons in Cathodic ray tubes is

limited by the electrostatic generators available

In the 1930s several generators where invented to

produce high electric fields

Ion source

acceleration steering analyzer

vacuum

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

12

Particle sources

bull How particles are first producedbull How to extract particles with the right

propertiesbull What are the limitations of the sourcesbull The quality of the source is very important If

the particles emitted by the source do not have the right properties it will be very difficult andor expensive to rectify it later

Beams of nanoamperes to hundreds of amperes

Very thin to very broad beams (μm2 to m2)

Negative to highly charged state

e to protein molecule

14

Emission of electronThermionic effect

(image source wikipedia)

When a metal is heated more electrons

can populate high energy levels

Above a certain threshold they

electrons can break their bound and be

emitted

This is thermionic emission

f=eminusEkBT

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Ion source

acceleration steering analyzer

vacuum

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

12

Particle sources

bull How particles are first producedbull How to extract particles with the right

propertiesbull What are the limitations of the sourcesbull The quality of the source is very important If

the particles emitted by the source do not have the right properties it will be very difficult andor expensive to rectify it later

Beams of nanoamperes to hundreds of amperes

Very thin to very broad beams (μm2 to m2)

Negative to highly charged state

e to protein molecule

14

Emission of electronThermionic effect

(image source wikipedia)

When a metal is heated more electrons

can populate high energy levels

Above a certain threshold they

electrons can break their bound and be

emitted

This is thermionic emission

f=eminusEkBT

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

12

Particle sources

bull How particles are first producedbull How to extract particles with the right

propertiesbull What are the limitations of the sourcesbull The quality of the source is very important If

the particles emitted by the source do not have the right properties it will be very difficult andor expensive to rectify it later

Beams of nanoamperes to hundreds of amperes

Very thin to very broad beams (μm2 to m2)

Negative to highly charged state

e to protein molecule

14

Emission of electronThermionic effect

(image source wikipedia)

When a metal is heated more electrons

can populate high energy levels

Above a certain threshold they

electrons can break their bound and be

emitted

This is thermionic emission

f=eminusEkBT

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

12

Particle sources

bull How particles are first producedbull How to extract particles with the right

propertiesbull What are the limitations of the sourcesbull The quality of the source is very important If

the particles emitted by the source do not have the right properties it will be very difficult andor expensive to rectify it later

Beams of nanoamperes to hundreds of amperes

Very thin to very broad beams (μm2 to m2)

Negative to highly charged state

e to protein molecule

14

Emission of electronThermionic effect

(image source wikipedia)

When a metal is heated more electrons

can populate high energy levels

Above a certain threshold they

electrons can break their bound and be

emitted

This is thermionic emission

f=eminusEkBT

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Beams of nanoamperes to hundreds of amperes

Very thin to very broad beams (μm2 to m2)

Negative to highly charged state

e to protein molecule

14

Emission of electronThermionic effect

(image source wikipedia)

When a metal is heated more electrons

can populate high energy levels

Above a certain threshold they

electrons can break their bound and be

emitted

This is thermionic emission

f=eminusEkBT

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

14

Emission of electronThermionic effect

(image source wikipedia)

When a metal is heated more electrons

can populate high energy levels

Above a certain threshold they

electrons can break their bound and be

emitted

This is thermionic emission

f=eminusEkBT

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

15

Emission of electron

Field effect

(image source answerscom)

Under a very intense electric

field some electrons will be

able to tunnel across the

potential barrier and become

free

This is known as field effect

emission

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

16

Emission of electron

Photo-electric effect

(image source wikipedia)

A photon incident on a piece of metal

can transfer its energy to an electron

If the photon transfers enough energy

the electron can be emitted

By using powerful lasers the

photoelectric effect can be used to

produce electron beams

This is known as the photo-electric

emission

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

17

Fermi-Dirac statistics

i

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

18

Work functionbull To escape from the metal the electrons must reach an

energy greater than the edge of the potential wellbull The energy that must be gained above the Fermi energy

is called the ldquowork functionrdquo of the metalbull The work function is a property

specific to a given metal It canbe affected by many parameters(eg doping crystaline statesurface roughness)

bull Example values

(image source wikipedia)

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

19

Summary electrons in solids

bull At low temperature all electrons are in the lowest possible energy level below the Fermi level

bull As the temperature increase some electrons will go above the Fermi level

bull But only those with an energy above the Fermi level greater than the work function are ldquofreerdquo

(im

ag

e s

ou

rce

htt

p

cn

xo

rgc

on

ten

tm

13

45

8la

tes

t

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

20

Thermionic emissionbull The Richardson-Dushman equation gives the electronic

current density J (Am-2) emitted by a material as a function of the temperature

With A the Richardson constant

(image source

Masao Kuriki ILC school)

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

21

Thermionic cathode materialbull Two parameters are important when considering a

thermionic cathode materialndash W=Work function (as low as possible)ndash Te=Operation Temperature (preferably high)

bull Cesium has a low work function (W~2eV) but a low operation temperature (Te=320K) =gt not good for high current

bull Metals Ta (41eV 2680K) W(45eV 2860K)bull BaO has good properties (1eV 1000K) but can oxidize by

exposure to air =gt sinter of BaO+WBaO provided slowly to the surface

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

22

Electric field bias

bull Once the electrons are free they may fall back on the cathode

bull To avoid this an electric field needs to be applied

bull If a negative potential is applied to the cathode the electrons will be attracted away from the cathode after being emitted

bull However this field affects the work function

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

24

Photo-electric emissionbull A photon incident on a

material will transfer its energy to an electron present in the metal

bull If the energy of this electron becomes bigger than the work function of the material the electron can be emitted

bull This is called photo-electric emission (image source

Masao Kuriki ILC school)

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

25

Photo-electric emission (2)

bull A UV photon at 200nm carries an energy of about 6 eV this is enough to ldquojumprdquo over the work function of most metals

bull As seen in electromagnetism electromagnetic waves (photons) can penetrate inside a metal

bull The photo-electricemission may thustake place away from the surface

(image source Dowell et al Photoinjectors lectures)

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

26

The 3 steps of photo-electric emission

Photo-electric emission takes place in 3 steps1) Absorption of a photon by an electron inside the metal The

energy transferred is proportional to the photon energy2) Transport of the photo to the physical surface of the metal

The electron may loose energy by scattering during this process

3) Electron emission (ifthe remaining energy isabove the work functionincluding Schottky effect)

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

27

Quantum efficiency (QE)bull For photo-electric emission it is useful to define the

ldquoquantum efficiencyrdquo

bull Typical QE for a photo-cathode is only a few percent or less

bull The quantum efficiency will decrease during the life of the cathode it may get damaged or contaminated

QE=Numberof photoelectronsNumberof photons

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

28

Examples

1) Which of these materials would give the highest thermionic emission current (at the same temperature)

(a) Iron (Fe) W=47 eV(b) Gadolinium (Gd) W=290 eV(c) Cobalt (Co) W=5 eV

2) Which laser would give the best Quantum efficiency on a Copper-based photo-cathode (W=5 eV)

(a) A 5GW CO2 laser (wavelength=10 micrometers)(b) A 10 kW frequency doubled NdYAG laser

(wavelength=532nm)(c)A 3MW frequency quadrupled Ti-Sapphire laser

(wavelength=200nm)

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Ion source SINCSSource of Negative Ions by Cesium Sputtering - SNICS II

Principle of Operation

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

liquid metal ion source (LMIS)

Focused Ion Beam

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Electrospray ionisation

Charge Residue Model electrospray droplets undergo evaporation and fission cycles eventually leading progeny droplets that contain on average one analyte ion or less The gas-phase ions form after the remaining solvent molecules evaporate leaving the analyte with the charges that the droplet carried

1 mbar 10-3 mbar 10-5 mbar 10-6 mbar

Rotarypump

Turbopump

TurbopumpHeated

Capillary(~180degC)

ESI needle4kV

Fused silicacapillary

Tube lens

Skimmer

OctapoleLenses

Acceleration tube

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Acceleration stage

bull Only works on charged particlesbull Electric Fields for Accelerationbull Magnetic Fields for Steering bull Magnetic fields act perpendicular to the direction of

motionbull For a relativistic particle the force from a 1 Tessla

magnetic field corresponds to an Electric field of 300 MVm

Lorentz Force

BvEqF

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

types of accelerators1048708 electrostatic (DC) accelerators1048708 Cockcroft-Walton accelerator (protons up to 2 MeV)1048708 Van de Graaff accelerator (protons up to 10 MeV)1048708 Tandem Van de Graaff accelerator (protons up to 20 MeV)

1048708 resonance accelerators1048708 cyclotron (protons up to 25 MeV)1048708 linear accelerators electron linac 100 MeV to 50 GeV1048708 proton linac up to 70 MeV

1048708 synchronous accelerators1048708 synchrocyclotron (protons up to 750 MeV)1048708 proton synchrotron (protons up to 900 GeV)1048708 electron synchrotron (electrons from 50 MeV to 90 GeV)

1048708Induction Induction linac betatron

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

electrostatic accelerators

generate high voltage between two electrodes charged particles move in electric fieldrArr

energy gain = charge times voltage drop

Cockcroft-Walton and Van de Graaff accelerators differ in method to achieve high voltage

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Cockroft-Walton High voltage source using rectifier units Voltage multiplier ladder (made of

diodes and capacitors) allows reaching up to ~1 MeV (sparking)

First nuclear transmutation reaction achieved in 1932 p + 7Li rarr 2middot4He

CW was widely used as injector until the invention of RFQ

Fermilab 750 kV C-W preaccelerator

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Van de Graaff Voltage buildup by mechanical

transport of charge using a conveyor belt up to ~20 MV

The charged particles are extracted from an ion source housed inside the high-voltage terminal and accelerated down an evacuated tube to ground potential

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Tandem Van de Graaff

Negative ions accelerated towards a positive HV terminal then stripped of electrons and accelerated again away from it doubling the energy

Negative ion source required

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

The Million Volt BarrierSummary of Problems in getting HV ~ 1929

Voltage Generators

Insulators ndash 750 kV max holding

Power

Safety in using HV

Funding

Imagination

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

RF Accelerators

High voltage gaps are very difficult to maintain

Solution Make the particles pass through the voltage gap many times

First proposed by G Ising in 1925

First realization by R Wiederoumle in 1928 to produce 50 kV potassium ions

Many different types

Radiofrequency oscillating voltage

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

RF LINAC ndash basic idea

Particles accelerated between the cavities

Cavity length increases to match the increasing speed of the particles

EM radiation power P = ωrfCVrf2 ndash

the drift tube placed in a cavity so that the EM energy is stored

Resonant frequency of the cavity tuned to that of the accelerating field

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

RF LINAC ndash phase focusing E M McMillan ndash V Veksler 1945

The field is synchronized so that the slower particles get more acceleration

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

History-Why

Particle Sources

Acceleration stage

Space charge

Diagnostics

Application

1Accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

What do you want to know about the beam

bull Intensity (charge) (IQ)

bull Position (xyz)

bull Sizeshape (transverse and longitudinal)

bull Emittance (transverse and longitudinal)

bull Energy

bull Particle losses

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Properties of a charged beam

bull Almost all accelerators accelerate charged particles which interact with matter

bull Thats almost all what you need to use to build diagnostics (together with some clever tricks)

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Faraday cup (1)

bull Lets send the beam on a piece of copper

bull What information can be measured after the beam has hit the copper

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Faraday cup (2)bull Two properties can be

measuredndash Beam total energyndash Beam total charge

bull By inserting an ammeter between the copper and the ground it is possible to measure the total charge of the beam

bull At high energy Faraday cups can be large More than 1m at DiamondImage source Pelletroncom

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Beam current monitor

bull Remember as the charge travelling in the beam pipe is constant the current induced on the walls (of the beam pipe) will be independent of the beam position

bull By inserting a ceramic gap and an ammeter the total charge travelling in a beam pipe can be measured

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Beam current monitor vs Faraday cup

bull Both devices have pros and cons

bull A Faraday cup destroys the beam but it gives a very accurate charge measurements

bull A Beam current monitor does not affect the beam but must be calibrated

bull Both tend to be used at different locations

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Screen (1)bull If a thin screen is inserted in

the path of the particles they will deposit energy in the screen

bull If this screen contains elements that emit light when energy is deposited then the screen will emit light

bull Example of such elements Phosphorus Gadolinium Cesium

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Screen (2)bull It is not possible to stay in

the accelerator while the beam is on so the screen must be monitored by a camera

bull To avoid damaging the camera the screen is at 45 degrees

bull On this screen you can see both the position of the beam and its shape

bull Note the snow on the image

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Wire-scannerbull By inserting a thin wire in

the beam trajectory (instead of a full screen) it is possible to sample parts of the beam

bull By moving the wire in the transverse direction one can get a profile of the beam

bull It is possible to use wire diameters of just a few micrometres

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Longitudinal properties

bull It is not possible to directly image the longitudinal profile of a bunch

bull By giving longitudinal impulsion to the beam it is possible to make it rotate and observe its longitudinal profile

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Beam losses

bull It is important to monitor the beam losses directly

bull Small beam losses may not be detected by other systems

bull Beam losses are a source of radiation and activation

bull Most beam losses indicate that there is a problem somewhere

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Limitation of these monitorsbull Monitors in which the

matter interacts are prone to damage

bull With high energy high intensity colliders such damages are more likely to occur

bull To the left hole punched by a 30 GeV beam into a scintillating screen

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Laser-wirebull To mitigate the problem of

broken wires in wire-scanners it is possible to replace the wire by a laser

bull This technique called ldquolaser-wirerdquo also allow to reach better resolutions

bull High power lasers (or long integration times) are needed

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Synchrotron radiation

bull Synchrotron radiation carries information about the beam which emitted it

bull It is commonly used to study the beam shape

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Energy measurements

bull To measure (or select) the energy of the particles a bending magnet is often the best solution

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Diagnostics overview

Charge

Charge Faraday cup

Position Screen BPM

Energy

Losses

Interaction with matter

Beam current monitor

Size or shape (transv)

Screen or wire-scannerLW

Synchrotron rad OTRODR

Size or shape (longit)

RF cavity + screen

Radiation detectors

Bending magnet

Scintillator

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Summarybull There are two ways of

measuring the properties of a beamndash By forcing it to interact

with matterndash By looking at the EM

radiation emittedbull How to build the best

diagnostic is then a matter of imagination

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

bull History-Whybull Particle Sourcesbull Acceleration stagebull Space chargebull Diagnosticsbull Application

1Accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Several accelerator based methods can be used to date old artefacts

Hospitals use accelerators everyday to treat some forms of Cancer

The data storage capacity of electronic devices has been improved

The structure of molecules including drugs can be studied with intense sources of X-rays

Material hardness can be studied with neutrons

Intense flux of neutrons can burn unwanted nuclear materials

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

The Shroud of Turin

The shroud of Turin is a piece of cloth which was first mentioned in the middle age

On it the face of a man can be seen

Some claim that it is the shroud that was used after the Christs crucifixion

In the 1980s 3 AMS laboratory independently dated the sample they were provided to 1260-1390

Dating old artefacts

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Therapy

Comparison of the physical dose distribution (upper diagram) and the survival rate of cells (lower diagram) as a function of penetration depth for ion and photon beams The enhanced energy deposition at the end of the particle range and the corresponding dramatic decrease of cell survival show that heavy ion beams are excellent tools for the treatment of deep seated tumours

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

therapy

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Sub-micron micromachining interactions

Masked processes (electromagnetic)bullLightbullX-rays

Direct write processesbullElectronsbullLow energy heavy ions (eg gallium)bullHigh energy light ions (protons)

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Proton Beam Micro-machining Examples of structures in PMGI and PMMA

(2 MeV proton beam)

Structures produced in a 12 mthick PMGI resist layer

Map of Singapore (60 m high) produced in bulk PMMA

Cogs (60 m high) produced in bulk PMMA

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Pharmaceutical drugs

To be efficient a drug need to target the correct molecule

This can only be achieved by studying the diffraction of intense on the molecule

What type of machine (gun accelerator ) is best suited to deliver an intense stable beam of X-rays

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

0 20 40 60 80

[d(A)2+H]+

Cou

nts

Time (ms)

Irradiation of dinucleotide ( 二核苷酸） cations [d(A)2+H]+ in ELISA The initial count rate after injection is due to the decay of lsquolsquohotrsquorsquo ions but after ca 20 ms the signal is dominated by collisional decay Laser excitation after 60 ms of storage time causes a large increase in the count rate The depletion of the ion beam is reflected in a lower rate of collisional decay after laser excitation than before

1 m

Accelerator with electrospray ion source

Magnet

Ion bunch

Na oven Microchannelplate detector

Channeltron detector

Fig23 Schematic drawing of electrostatic storage ring (ELISA)

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

HIRFLHIRFL

回旋1

回旋2

具有全离子宽能区的特点

治癌

电子冷却

电子冷却

HIRFL-CSR是重离子物理及相关学科研究的

综合性实验平台兰兰州州重重离离子子加加速速器器

ECR源

核物理粒子物理

原子物理

核物理核天体物理

应用物理

79

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

实现重离子束深层癌症临床治疗研究

109 个离子 治癌

回旋加速器

同步加速器均匀慢引出

成功治疗了 45例患者肝癌肺癌胰腺癌脑胶质瘤恶性脑膜瘤头颈部肿瘤骨和软组织肉瘤直肠癌前列腺癌卵巢癌等

主要创新采用回旋与同步组合的独特治癌专用机器模式打破了国外相关行业对我国的专利禁锢

2008-2011 利用物理实验的间隙 实现笔形束点扫描

达到适形治疗

80

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

ProducerWuxi EL PONT Accelerator Research Institute 无锡爱邦httpwwwelpontnetabfsENHV High Voltage Engineering Europa BV

httpwwwhighvoltengcomNational Electrostatics Corporation (NEC) httpwwwpelletroncomindexhtmlKobelcohttpwwwkobelcocojpenglishmachineryproductsfunctionhrbsindexhtmlIBAhttpwwwiba-industrialcome-beam-accelerators

Accelerators do not operate on their own

A team is needed to manage the accelerator operations

All accelerators facilities have a wide-range of staff at all levels

There are also many jobs connected to the usage of accelerators

New machines bring new challenges and there are many opportunities for graduate studies in Accelerator science

Jobs and graduate studies

bull Timothy Koethbull Physics Oxford Universitybull www-w2kgsidecharmsTalksCHARMSbull Greg LeBlancbull 盛丽娜bull 刘波

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bull Timothy Koethbull Physics Oxford Universitybull www-w2kgsidecharmsTalksCHARMSbull Greg LeBlancbull 盛丽娜bull 刘波

• Slide 1
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