Philip Burrows Otago University, Dunedin 13/10/081

or

Making subatomic particles go very fast!

Philip Burrows

John Adams Institute, Oxford University

Visiting Oxford Fellow, Canterbury University

Particle Accelerators

Philip Burrows Otago University, Dunedin 13/10/082

Large Hadron Collider (LHC)

Largest,

highest-energy

particle

collider

CERN,

Geneva

Philip Burrows Otago University, Dunedin 13/10/083

In case you missed it …

All eyes on collider as it comes to life

Will atom smasher signal end of the world?

Le LHC, un succès européen à célébrer

Large Hadron Collider e International Linear Collider a caccia del bosone di Higgs

Wir stoßen die Tür zum dunklen Universum auf

Philip Burrows Otago University, Dunedin 13/10/084

Large Hadron Collider (LHC)

Largest,

highest-energy

particle

collider

CERN,

Geneva

First protons September 10th

Philip Burrows Otago University, Dunedin 13/10/085

Philip Burrows Otago University, Dunedin 13/10/086

Large Hadron Collider (LHC)

Largest,

highest-energy

particle

collider

CERN,

Geneva

Philip Burrows Otago University, Dunedin 13/10/087

The fastest racetrack on the planet

The protons will

reach

99.9999991%

speed of light,

and go round the

27km ring 11,000

times per second

Philip Burrows Otago University, Dunedin 13/10/088

The emptiest vacuum in the solar system

Ten times more atmosphere on the Moon than inside LHC beam pipes

Philip Burrows Otago University, Dunedin 13/10/089

The coldest places in the galaxy

The LHC operates at -271 C (1.9K),

colder than outer space.

A total of 36,800 tonnes are cooled to this temperature.

The largest refrigerator ever

Philip Burrows Otago University, Dunedin 13/10/0810

The hottest spots in the galaxy

When the two beams of protons collide, they will generate temperatures

1000 million times hotter than the heart of the sun,

but in a minuscule space

Philip Burrows Otago University, Dunedin 13/10/0811

The biggest detectors ever built

Philip Burrows Otago University, Dunedin 13/10/0812

The biggest detectors ever built

To sample and record the debris from up to

600 million proton collisions per second,

we are building gargantuan devices

to measure particles with micron precision.

Philip Burrows Otago University, Dunedin 13/10/0813

The most extensive computer system

To analyse the data

tens of thousands of computers

around the world are being harnessed in the Grid

Philip Burrows Otago University, Dunedin 13/10/0814

First event 10 September 2008

Philip Burrows Otago University, Dunedin 13/10/0815

Why build accelerators?

Philip Burrows Otago University, Dunedin 13/10/0816

Uncovering the origin of the universe

Older ….. larger … colder ….less energetic

nowBig Bang

Philip Burrows Otago University, Dunedin 13/10/0817

Telescopes to the early universe

Older ….. larger … colder ….less energetic

nowBig Bang

Philip Burrows Otago University, Dunedin 13/10/0818

Composition of the universe

Philip Burrows Otago University, Dunedin 13/10/0819

Why build accelerators?

• Want to see what matter is made of

• Smash matter apart and look for the building blocks

• Take small pieces of matter:

accelerate them to very high energy

crash them into one another

• LHC: protons crashing into protons head-on

Philip Burrows Otago University, Dunedin 13/10/0820

Why colliders?

The higher the energy, the smaller the pieces we can reveal in the collisions

Philip Burrows Otago University, Dunedin 13/10/0821

Why colliders?

The higher the energy, the smaller the pieces we can reveal in the collisions

60 mph stationary

Philip Burrows Otago University, Dunedin 13/10/0822

Why colliders?

The higher the energy, the smaller the pieces we can reveal in the collisions

60 mph stationary

30 mph 30 mph

Philip Burrows Otago University, Dunedin 13/10/0823

Why colliders?

The higher the energy, the smaller the pieces we can reveal in the collisions

60 mph stationary

30 mph 30 mph

For speeds

well below

light speed:

same damage!

Philip Burrows Otago University, Dunedin 13/10/0824

Why colliders?

Philip Burrows Otago University, Dunedin 13/10/0825

Why colliders?

Now try this with protons moving near light speed

stationary

Philip Burrows Otago University, Dunedin 13/10/0826

Why colliders?

Now try this with protons moving near light speed

stationary

Philip Burrows Otago University, Dunedin 13/10/0827

Why colliders?

stationary

For the same physics,

14,000 times the energy

of each proton in the LHC

Philip Burrows Otago University, Dunedin 13/10/0828

Why colliders?

Most of the energy goes into carrying the momentum forward

Philip Burrows Otago University, Dunedin 13/10/0829

Why colliders?

All the energy available for smashing up the protons

Philip Burrows Otago University, Dunedin 13/10/0830

High energy is critical

Size of structure we can probe with a collider like LHC

= h / p (de Broglie, 1924)

h = Planck’s constant = 6.63 x 10**-34 Jsp = momentum of protons

The larger the momentum (energy), the smaller the size

Philip Burrows Otago University, Dunedin 13/10/0831

How to accelerate protons to high energies?

protons carry electric CHARGE feel electric force

proton

Philip Burrows Otago University, Dunedin 13/10/0832

Accelerating protons

Apply an electric field accelerate!

Philip Burrows Otago University, Dunedin 13/10/0833

Accelerating protons

Apply an electric field accelerate!

Philip Burrows Otago University, Dunedin 13/10/0834

Accelerating protons

Apply an electric field accelerate!

+ -

V

Philip Burrows Otago University, Dunedin 13/10/0835

Accelerating protons

Apply an electric field accelerate!

+ -

V

Philip Burrows Otago University, Dunedin 13/10/0836

Accelerating protons

Apply an electric field accelerate!

+ -

V

Philip Burrows Otago University, Dunedin 13/10/0837

Accelerating electrons

+ -

V

Philip Burrows Otago University, Dunedin 13/10/0838

Accelerating electrons

+ -

V

Philip Burrows Otago University, Dunedin 13/10/0839

Accelerating electrons

+ -

V

Energy ~ voltage

Philip Burrows Otago University, Dunedin 13/10/0840

The early days

Philip Burrows Otago University, Dunedin 13/10/0841

The early days

+-

Philip Burrows Otago University, Dunedin 13/10/0842

The early days

X-rays

Philip Burrows Otago University, Dunedin 13/10/0843

First use of an accelerator in medicine!

Mrs. Roentgen’s

hand

Philip Burrows Otago University, Dunedin 13/10/0844

Cockcroft – Walton Accelerator

800,000 Volts

Philip Burrows Otago University, Dunedin 13/10/0845

Van de Graaff Accelerator

1500,000 Volts

Philip Burrows Otago University, Dunedin 13/10/0846

How many Volts???

Voltage [Volts] Size probed [metres]

Philip Burrows Otago University, Dunedin 13/10/0847

How many Volts???

Voltage [Volts]

1000,000 (Mega)

Size probed [metres]

0.000 000 000 000 1

Philip Burrows Otago University, Dunedin 13/10/0848

How many Volts???

Voltage [Volts]

1000,000 (Mega)

1000,000,000 (Giga)

Size probed [metres]

0.000 000 000 000 1

0.000 000 000 000 000 1

Philip Burrows Otago University, Dunedin 13/10/0849

How many Volts???

Voltage [Volts]

1000,000 (Mega)

1000,000,000 (Giga)

1000,000,000,000 (Tera)

Size probed [metres]

0.000 000 000 000 1

0.000 000 000 000 000 1

0.000 000 000 000 000 000 1

Philip Burrows Otago University, Dunedin 13/10/0850

How many Volts???

Voltage [Volts]

1000,000 (Mega)

1000,000,000 (Giga)

1000,000,000,000 (Tera)

LHC:

7000,000,000,000

7 trillion Volts

Size probed [metres]

0.000 000 000 000 1

0.000 000 000 000 000 1

0.000 000 000 000 000 000 1

0.000 000 000 000 000 000 01

10**-20 metres

Philip Burrows Otago University, Dunedin 13/10/0851

How to reach LHC energies?

• We need 7000,000,000,000 Volts /proton beam

How to do this??

Philip Burrows Otago University, Dunedin 13/10/0852

How to reach LHC energies?

• We need 7000,000,000,000 Volts /proton beam

How to do this??

?

Philip Burrows Otago University, Dunedin 13/10/0853

How to reach LHC energies?

• We need 7000,000,000,000 Volts /proton beam

How to do this??

?• Would need 10,000,000,000,000 AA batteries

Philip Burrows Otago University, Dunedin 13/10/0854

How to reach LHC energies?

• We need 7000,000,000,000 Volts

How to do this??

?• Would need 10,000,000,000,000 AA batteries• 5 x 10**11 m = 3 x Earth’s orbit radius around Sun

Philip Burrows Otago University, Dunedin 13/10/0855

How to reach LHC energies?

• We need 7000,000,000,000 Volts

How to do this??

?• Would need 10,000,000,000,000 AA batteries• 5 x 10**11 m = 3 x Earth’s orbit radius around Sun• $30,000,000,000,000 – discount for bulk buy?!

Philip Burrows Otago University, Dunedin 13/10/0856

Accelerating Technology

• Batteries have too low voltage per metre:

1.5 Volts per 5 cm = 30 Volts / m (‘gradient’)

Philip Burrows Otago University, Dunedin 13/10/0857

Accelerating Technology

• Batteries have too low voltage per metre:

1.5 Volts per 5 cm = 30 Volts / m (‘gradient’)

• Forefront accelerating gradients ~ 30 MILLION Volts / m

• Hence largest accelerator (LHC) is **ONLY** 27 km long!

Philip Burrows Otago University, Dunedin 13/10/0858

Accelerating Technology

• Batteries have too low voltage per metre:

1.5 Volts per 5 cm = 30 Volts / m (‘gradient’)

• Forefront accelerating gradients ~ 30 MILLION Volts / m

• Hence largest accelerator (LHC) is **ONLY** 27 km long!

• Accelerate using radio-frequency EM waves launched

into metal cavities …

• Protons gain energy by ‘surfing’ the waves

Philip Burrows Otago University, Dunedin 13/10/0859

Niobium Accelerating Structures

Philip Burrows Otago University, Dunedin 13/10/0860

Human surfer

Philip Burrows Otago University, Dunedin 13/10/0861

Subatomic surfer

+

-

+

Electro-

magnetic wave

E

Philip Burrows Otago University, Dunedin 13/10/0862

Large Hadron Collider (LHC)

Philip Burrows Otago University, Dunedin 13/10/0863

More about LHC

• 27km tunnel is 50 – 150 m below ground

Philip Burrows Otago University, Dunedin 13/10/0864

More about LHC

• 27km tunnel is 50 – 150 m below ground

• Two beams of protons circulating in opposite directions

• Beams controlled by 1800 superconducting magnets (8 T)

Philip Burrows Otago University, Dunedin 13/10/0865

More about LHC

• 27km tunnel is 50 – 150 m below ground

• Two beams of protons circulating in opposite directions

• Beams controlled by 1800 superconducting magnets (8 T)

• Each beam contains 3000 ‘bunches’ of protons

• Each bunch contains 200 billion protons

Philip Burrows Otago University, Dunedin 13/10/0866

More about LHC

• 27km tunnel is 50 – 150 m below ground

• Two beams of protons circulating in opposite directions

• Beams controlled by 1800 superconducting magnets (8 T)

• Each beam contains 3000 ‘bunches’ of protons

• Each bunch contains 200 billion protons

• 600 million proton-proton collisions per second

Philip Burrows Otago University, Dunedin 13/10/0867

Large Hadron Collider (LHC)

Will give us a first look at

new physics landscape.

Panoramic view,

but with low resolution:

‘broad-band’ survey:

A precision microscope (‘narrow-band’ instrument) is

needed to illuminate the features in the new landscape …

Philip Burrows Otago University, Dunedin 13/10/0868

International Linear Collider

31 km

Philip Burrows Otago University, Dunedin 13/10/0869

Linear Colliders for electrons + positrons

Stanford

Linear

Accelerator

Center

(California)

Philip Burrows Otago University, Dunedin 13/10/0870

Accelerators Worldwide

• High-energy accelerators 120

• Synchrotron radiation X-ray sources 100

Philip Burrows Otago University, Dunedin 13/10/0871

Diamond: synchrotron source of X-rays

Philip Burrows Otago University, Dunedin 13/10/0872

Accelerators Worldwide

• High-energy accelerators 120

• Synchrotron radiation X-ray sources 100

• Radiotherapy7700

• Biomedical research 1000

Philip Burrows Otago University, Dunedin 13/10/0873

Clatterbridge: cancer treatment w protons

Philip Burrows Otago University, Dunedin 13/10/0874

Accelerators Worldwide

• High-energy accelerators 120

• Synchrotron radiation X-ray sources 100

• Radiotherapy 7700

• Biomedical research 1000

• Industrial processing 1500

• Ion implanters, surface modification 7000

Total 17,500

Philip Burrows Otago University, Dunedin 13/10/0875

Large Hadron Collider (LHC)