asac introduction

8/3/2019 ASAC Introduction

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MIT X-ray Laser ProjectA true x-ray laser will have enormous impact

No x-ray source is coherentNo laser has much power for l < 30 nm

Murnane and Kapteyne produced l=31nm

light pulses with a nano-Joule per pulse

The number of photons per quantum state,

the photon degeneracy is less than 0.1


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X-ray Lasers: Promise to be a comprehensive probe of all spatial and

temporal scales and resolutions relevant to condensed matter

Spatial Scales Temporal Scales


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MIT X-ray Laser Project

Unique opportunity to integrate:

Accelerator technology

(MIT/Bates Lab)

Fast laser technology

(MIT Ultrafast Group)


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Self-Amplified Spontaneous Emission (SASE)

SASE Radiation has full Transverse Coherence


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APS DemonstratesSelf-Amplified Spontaneous Emission (SASE)


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SASE Radiation is not Transform Limited

310/ =cle

NN

310/ el NNc

A SASE FEL is an amplifier of electron density modulations


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SASE Radiation is Powerful, But Noisy

t (fs) Dw/w (%)


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Seeding to Limit Fluctuations


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Data from BNL DUV-FEL experiment


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Seeded beam SASE beam

Output

wavelength

FEL param

rFEL

Dtmin (fs) at

max BW

DEmin (meV) at

1 ps FWHM

SASE Dtmin

(fs)

SASE DEmin

(meV)100 nm 9.e-3 20 2 100 110

10 nm 4.e-3 5 2 100 500

1 nm 1.5e-3 1 2 100 1900

0.1 nm 0.2e-3 0.8 2 100 2500

Bandwidth and Pulse Length

1

2f tD D

FELf fr

D=

Seeded beams limited only by

uncertainty principle and seed

properties.

SASE properties determinedby ebeam.


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Provide full transverse and longitudinal coherence get rid of the SASE noise

Provide wide spectrum coverage: 100 nm > l


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How to reach wavelengths below 1 nm?

Must get the shortest wavelength seeds

using High Harmonic Generation methods,--30nm available now, possible 10 nm or below

Then use cascaded High Gain

Harmonic Generation methods in FEL,--factors of >30 are possible


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-4 -2 0 2 4Time, fs

x-ray harmonicemission=

=/

MIT Ultra-fast GroupHHG seeding methods

J. Fujimoto, H. Haus, E. Ippen, F. Kaertner

See current issue of Physics Today


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High-Harmonic Generation

Noble Gas Jet (He, Ne, Ar, Kr)

100 mJ - 1 mJ@ 800 nm

XUV @ 3 30 nm

h = 10-8 - 10-5

Recombination

Propagation

-Wb

wXUV

Energy

t

x

tb

0

Laser electric field

Ionization


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High Gain Harmonic Generation

Modulator is tuned tow0.

Electron beamdevelops energy

modulation at w0.

3rd harmonicbunching isoptimized inchicane.

Energy modulation is

converted to spatial

bunching in chicane

magnets.

Input seed at w0

overlaps electron

beam in energy

modulator undulator.

Electron beam radiates

coherently at w3 in long

radiator undulator.

Radiator is tuned to w3.

Method to reach short wavelength FEL output from longer

wavelength input seed laser.


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Cascaded HGHG

Input

seed w01st stage 2nd stage 3rd stage

Output at 3w0

seeds 2nd stage

Output at 9w0

seeds 3rd stage

Final output

at 27w0

Number of stages and harmonic of each to be optimized during study.

Factor of 10 30 in wavelength is reasonable without additional

acceleration between stages.

Seed longer wavelength (100 10 nm) beamlines with ~200 nm harmonic

from synchronized Ti:Sapp laser.

Seed shorter wavelength (10 0.3 nm) beamlines with HHG pulses.


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Laser System & SynchronizationHigh Harmonic

Generation

1 nJ 10 nJ

100 as 10 ps

1-20 kHz

@ 1 - 30 nm

Photo-Injector:

1-10 ps Pulses

1-10 mJ

1-20 kHz

@ 266 nm(conv. NLO)

Fiberlink + Synchronization

LINAC FELE-beam

~200 m

10 fsTiming Jitter

Output: Three highly synchronized pulse streamsE-beam, EUV 1 - 30 nm and @ 800 nm driver pulse


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0.3 nm 0.1 nm

UV Hall X-ray Hall

Nanometer Hall

SC Linac

4 GeV2 GeV1 GeV

1 nm

0.3 nm

100 nm

30 nm

10 nm

10 nm

3 nm

1 nm

Main oscillator

Pump

laserPump

laser

Seed

laser

Seed

laser

Seed

laser

Pump

laser

Fiber link synchronization

Injector

laser

Undulators

Undulators

Undulators

Upgrade: 0.1 nm

at 8 GeV

SC Linac

MIT X-ray Laser Concept


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to master oscillator for timing sync

Pump

lasersTi:Sapp + BBO = 200 nm seed

Ti:Sapp + HHG = 10-30 nm seed

Tune by OPA or harmonic number

10 nm

3 nm

1 nm

Direct seeded or cascaded

HGHG undulators

Nanometer Hall

Seed

lasers

Ti:Sapp + HHG = 10-30 nm seed

Tune by OPA or harmonic number

Cascaded HGHG undulators

Cascaded HGHG undulators

~20 m length

10 GW peak

~30 m length

4 GW peak


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Pulse Structure (Quasi-CW)

SC Linac Pulse @1Hz 10% Duty Factor

0 500 1000 1500 2000 2500

Time (ms)

~90 Warm RF Gun Pulses 1 ms spacing

0 100

Time (ms)

RF Gun Pulse

-10 0 10 20Time (us)

0.1% Duty Factor

8 Pulses

8 Beamlines

~500 pC / Pulse

1 us spacing


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Seeding for short pulse

0.2995 0.3 0.3005 0.3010

200

400

600

800

1000

Wavelength (nm)

Power(kW/bin)

0.2995 0.3 0.3005 0.3010

200

400

600

800

1000

Wavelength (nm)

Power(kW/bin)

Output time profile Time profile (log plot) Spectrum

0 10 20 30 40 5010

0

102

104

106

108

1010

Time (fs)

Power(W)

0 10 20 30 40 5010

0

102

104

106

108

1010

Time (fs)

Power(W)

Seed laser parameters

FWHM 0.5 fs

Power 10.0 MW

Pulse energy 5 nJ

FEL output parameters

Saturation FWHM 0.75 fs

Saturation power ~2.0 GW

Saturation energy 1.5 mJ

FWHM linewidth 6.0E-4

Undulator length 20 m

GINGER simulation of

seeded FEL at 0.3 nm.

Same ebeam parameters as SASE case.

0 10 20 30 40 500

0.5

1

1.5

2

Time (fs)

Power(GW)

0 10 20 30 40 500

0.5

1

1.5

2

Time (fs)

Power(GW)

24.5 25 25.5 26 26.5 270

0.5

1

1.5

2

Time (fs)

Power(GW)

24.5 25 25.5 26 26.5 270

0.5

1

1.5

2

Time (fs)

Power(GW)


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Seeding for narrow linewidth

Output time profile Time profile (log plot) Spectrum

Seed laser parameters

FWHM 50 fs

Power 0.1 MW

Pulse energy 5 nJ

FEL output parameters

Saturation FWHM 30 fs

Saturation power ~2.0 GW

Saturation energy 0.1 mJ

FWHM linewidth 1.0E-5

Saturation length 28 m

GINGER simulation of

seeded FEL at 0.3 nm.

Same ebeam parameters as SASE case.

0.2995 0.3 0.3005 0.3010

100

200

300

400

500

Wavelength (nm)

Power(MW/bin)

0.2995 0.3 0.3005 0.3010

100

200

300

400

500

Wavelength (nm)

Power(MW/bin)

0 10 20 30 40 500

0.5

1

1.5

2

Time (fs)

Power(GW)

0 10 20 30 40 500

0.5

1

1.5

2

Time (fs)

Power(GW)

0 10 20 30 40 5010

0

102

104

106

108

1010

Time (fs)

Power(W)

0 10 20 30 40 5010

0

102

104

106

108

1010

Time (fs)

Power(W)


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Comparison of SASE and Seeded Sources with APS Undulator A


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Cost Basis

Fixed Costs 80 M$

(Gun, X-ray Beamlines, Buildings, Cryoplant, Controls)

Linac Systems (20 MeV/m, ~0.4M$/m) 20 M$/GeV

Undulator Systems (0.2 M$/m)

20M$/100mTotal Undulator Length = 4 x longest saturation length

Contingency 25%


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Example

4 GeV Linac

50 m Saturation Length

Costs: 80 M$ Fixed

80 M$ Linac

40 M$ Undulators

50 M$ Contingency------------

250 M$ Total


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1

10

100

1000

0 5 10 15 20

Electron Energy (GeV)

SaturationLength(m)


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1

10

100

1000

0 5 10 15 20


SaturationLength(m)

100 nm

Electron Bunch ParametersQ = 0.5 nC E/E = 0.02% T = 250 fs

= 1.5 m

Hybrid Undulator ParametersVISA: = 18 mm, K=1.4, B=0.8 T23mm: = 23 mm, K=2.4, B=1.1 T

LCLS: = 30 mm, K=3.9, B=1.4 T

10 nm

1 nm

0.3 nm

0.1 nm

0.15 nm (LCLS)

u = 18 mmu = 23 mm

u = 30 mm

H b id U d l t P t

Better GunS d ti U d l t


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1

10

100

1000

0 5 10 15 20


SaturationLength(m)

100 nm

Electron Bunch ParametersQ = 0.5 nC E/E = 0.02% T = 250 fs

= 1.5 m

Hybrid Undulator ParametersVISA: = 18 mm, K=1.4, B=0.8 T23mm: = 23 mm, K=2.4, B=1.1 TLCLS: = 30 mm, K=3.9, B=1.4 T

10 nm

1 nm

0.3 nm

0.1 nm

= 0.75 mSuperconducting Undulator = 14 mm K = 1.3

Superconducting UndulatorMiracle Gun = 0.1 m


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Essential to Improve e-Gun Performance

In linacs, electron emittances scale inversely with energy

Electron beam emittance is born at the electron gun

Electron gun emittances today are ee = 0 .5 nm/E (GeV)

Photon emittances for full transverse coherence ep = lp/4

To couple a given electron beam most effectively to a

coherent photon field, we should have:

ee = ep


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0.3 nm 0.1 nm

UV Hall X-ray Hall

Nanometer Hall

SC Linac

4 GeV2 GeV1 GeV

1 nm

0.3 nm

100 nm

30 nm

10 nm

10 nm

3 nm

1 nm

Main oscillator

Pump

laserPump

laser

Seed

laser

Seed

laser

Seed

laser

Pump

laser

Fiber link synchronization

Injector

laser

Undulators

Undulators

Undulators

Upgrade: 0.1 nm

at 8 GeV

SC Linac

MIT X-ray Laser Concept


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The MIT X-ray Laser Project

A National User Facility: 10-30 beams

Wavelength range 100-0.1 nm

Integrated laser seeding for full coherence

Pulses: Dt=1-1000 fs; Dw=3-0.003eV

Pulse power of up to 1 mJ

Pulse rates of 1 kHz or greater

MIT/ Bates Laboratory

Science:single molecule imaging,femtochemistry, nanometer lithography

Technology:superconducting FEL,Ti:Sapp HHG seeding technology

Education:accelerator science curriculum, synergy with CMSE programs

Cost/Schedule:$300M; design: FY04-FY06; construct: FY07-FY10


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MIT Commitment

MIT has embraced the x-ray laser conceptexclusively for the future of Bates Laboratory

Deans of Science and Engineering and the VP of

Research provided over $400K in seed support

President Vest asked a key CEO to chair a

corporation-level advisory committee to securesupport of business and political leaders in MA


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Charge to

MIT X-ray Laser

Accelerator Science Advisory Committee

September 18-19, 2003

The proposed MIT x-ray laser facility is at an early stage ofconceptual design. The goals of the design are to produce fully

coherent x-ray pulses with the stable and reliable operations

required of a user facility. We seek guidance and constructive

criticism regarding the technical choices that are being made.


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The ASAC committee should:

Review laser and accelerator sections of proposal to NSF and

technical presentations at committee meeting.Evaluate the appropriateness of chosen technologies and suggest

alternatives.

Identify the primary technical challenges for each system and for

the facility as a whole.

Respond to NSF reviewer comments.

Evaluate the potential for a facility based on the Bates linac to

demonstrate laser seeding and cascaded HGHG, and selectedscientific applications


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MIT X-ray Laser Design Proposal

Contact: David E. Moncton, Director

Telephone: 617-253-83333

E-mail: [email protected]

website: http://mitbates.mit.edu/xfel/indexpass.htm

Bates Senior Staff Contributors

Manouchehr Farkhondeh William M. Fawley James Fujimoto

Jan van der Laan Hermann Haus Erich Ippen

Christoph Tschalaer Ian McNulty Denis B. McWhan

Fuhua Wang Jianwei Miao Michael Pellin

Abbi Zolfaghari Mark Schattenburg Gopal K. Shenoy

Townsend Zwart

Co-Principal Investigators Science Collaborators

William S. Graves Simon Mochrie Keith A. Nelson

Franz X. Kaertner Gregory Petsko Dagmar Ringe

Richard Milner Henry I. Smith Andrei Tokmakoff

3-year duration, $15M total request


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Existing Technology

Electron Guns

Adequate performance has been demonstrated.

Room for continuing R&D and improvement.

Not a cost driver.


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Existing Technology

Linac

Successful operation at Tesla Test Facility, JLAB.

Capital cost driver.


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Existing Technology

Undulator

Well established. Successful experience at LEUTL, TTF.

Make use of investment in LCLS design.

Capital Cost driver.


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3 e r st d l n


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3-year study plan


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asac introduction

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