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Capri, 3 Giugno 2003

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Capri, 3 Giugno 2003
Esperimenti con fasci di elettroni brillanti
per la fase 2 di SPARC
Luca Serafini - INFN / Milano
• High Brightness e- Beams & TW Power Photon Beams :
Applications for SPARC-II
• Velocity Bunching (CORA) : production of ultra-short bunches
• Ultra-High Gradient Acceleration :
a 2nd generation Plasma Acceleration experiment
• A Source of Mono-chromatic X-Rays for
advanced clinical diagnostics
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Transverse Brightness of Electron Beams
Bn 
2I
 nx  ny
 A 

m2 rad 2 

I = peak current
nx = rms normalized transverse emittance
Quality Factor : beam peak current density normalized
to the rms beam divergence angle (linked to transverse beam coherence)
Round Beam : nx = ny , J = I /s2
s   nb 
s

s’low
s’s/b
b
2J
2Js 2
Bn 
2 
2

s

 
n
z
x’
s’high
x
seq
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Brightness is crucial for many Applications
Lg 
32

K Bn 1  K 2 2

SASE FEL’s
Courtesy of D. Umstadter, Univ. of Michigan
n  
 p  50 m
n p  p
 p  30  100 m
n p 2
Plasma Accelerators
NX  T f
N  N h
e
nb
*
 ; b  sz
*
Relativistic Thomson Monochromatic X-Ray Sources
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Three Generations of Electron Sources
• Thermo-Ionic
time-scale
Qbunch=1-100 nC
Bn=1010 A/(m.rad)2 s  ns (ps with RF bunchers) I=0.1 
10 A DC Diode (triode) with thermoionic cathode E ≈10 MV/m
• Photo-Injectors
time-scale
Bn=1015 A/(m.rad)2
ps
 100 A RF Cavity with photo-cathode
MV/m
• Plasma Guns
time-scale
Bn =1014-1015 A/(m.rad)2
fs
Langmuir waves in cold plasmas +
local wave-breaking
Capri, 3 Giugno 2003
Qbunch=0.1-10 nC
I=10
E ≈50-150
Qbunch=1-10 pC
I≈ 1 kA
E ≈ 1-10 GV/m
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Achieved Brightness in RF Photo-Injectors
TTF photo-inj. (achieved) 6.1012
exit of linac (compr.) 2.1013
ATF photo-inj. (achieved) 5.1013
@ photocathode
1.2.1015
Max. achievable without compr. n-cath =thermal
LCLS (requested @ 15 GeV) 4.1015
nx =ny=1.5 m
Bn 
2I
 nx  ny
I = bunch peak current
ESRF (storage ring) < 1014
nx =20 m ny=0.07 m
SPARC ultimate goal (Ph. 2) 2.1015
Capri, 3 Giugno 2003
 A 

m2 rad 2 

“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Wide International Community on
High Brightness Beams
THE PHYSICS OF HIGH BRIGHTNESS BEAMS
Proc. of the 2nd ICFA Advanced Accelerator Workshop
University of California, Los Angeles, Nov. 1999
edited by James Rosenzweig & Luca Serafini
Web page: www.physics.ucla.edu/AABD
Per vedere questa immagine
occorre QuickTime™ e un
decompressore GIF.
Physics and Science with the X-ray Free-Electron Laser
(Arcidosso, Italy, September 10-15, 2000)
C. Pellegrini and M. Cornacchia
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Velocity Bunching:
integrated compression in photoinjectors
Courtesy of D. Yeremian, SLAC
Slow wave structure
Standard v=c structure
 r 27 ; b r 0.9993
1000
100
800
80
Compression during
acceleration
I [A]
Current scaling
with energy
400
60
40
200
20
I/ = const.
0
0
0
Capri, 3 Giugno 2003
2
4
6
Z [ m]
8
10
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
T [MeV]
600
Trapped trajectories in a slow wave:
the Hamiltonian model @ a≈ 1
• If the phase velocity of the wave is ~c
k  k0  k 
r 

c
 k
k0

ck

; br  1 
2k
2ck

H    br  2 1  a cos 
 4a r2
  kz  t   0
eE0
a 2
mc k
Phase space plot s for a slow wave
with resonant gamma  r 12 and a  0.2
Top of the separatrix at  max  4a 2r
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
A quarter synchrotron oscillation
gives phase compression
• By Injecting at    r and extracting at   0 we perform an
energy spread enhancement associated to a phase spread
reduction
Beam run off-crest
‘chirps’ and compresses
rf wave
Courtesy of S. Anderson
Zoom-in of the diagram plot ted in previous transp. corresponding to   20 .
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
z =1 .5
z =3
0
-1.5
-1
-0.5
0
0 .5
1
1 .5
2
-1.5
-1
-0.5
0
0 .5
1
1 .5
1
Bu nc hi n g
0
-2
Dz [m m]
z =1 0
1
Bu nc hi n g
0
-2
z =4 .5
1
Bu nc hi n g
Bu nc hi n g
1
Bu nc hi n g
z =0 .3
1
0
2
-2
-1.5
-1
-0.5
Dz [m m]
0
0 .5
1
1 .5
2
0
-2
-1.5
-1
-0.5
Dz [m m]
0
0 .5
1
1 .5
2
-2
-1.5
-1
-0.5
Dz [m m]
0
0 .5
1
1 .5
2
Dz [m m]
3
rms norm. emittance [um]
2.5
beam current [kA]
2
LCLS Photoinjector
with RF Compression
1.5
1
0.5
Gun
Linac
0
0
2
4
6
3 solenoids for
additional focusing
z =0 .3
z =1 .5
1 00
Z_[m]
z =3
1 00 0
8
10
2 solenoids for
additional focusing
z =4 .5
3 00 0
z =1 0
6 00 0
6 00 0
4 00 0
4 00 0
2 00 0
50
5 00
-50
0
-50 0
DE _[Ke V]
0
DE _[Ke V]
DE _[Ke V]
DE _[Ke V]
DE _[Ke V]
1 00 0
0
2 00 0
2 00 0
0
0
-20 00
-20 00
-10 00
-10 0
-10 00
-20 00
Capri, 3 Giugno 2003
-15 0
-15 00
-2
-1.5
-1
-0.5
0
DZ_[mm ]
0 .5
1
1 .5
2
-2
-1.5
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
-30 00
-1
-0.5
0
DZ_[mm ]
0 .5
1
1 .5
2
-40 00
-2
-1.5
-1
-0.5
0
DZ_[mm ]
0 .5
1
1 .5
2
-2
-1.5
-1
-0.5
0
DZ_[mm ]
0 .5
1
1 .5
2
-40 00
-2
-1.5
-1
-0.5
0
DZ_[mm ]
0 .5
1
1 .5
2
First PARMELA Simulation
of RF Compressor
C. Ronsivalle
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
RF Compression at DUVFEL
P. Piot et al., PRSTAB 6 (2003) 033503
undulators
linac (off)
75 MeV
dump
Capri, 3 Giugno 2003
dump
linac
75 MeV
5 MeV
DUVFEL
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Initial Velocity Compression
Measurements at Livermore/Pleiades
Autocorrelation Signal (normalized)
Compressed Beam
Pulse Length Measurement
1.2
1
0.8
0.6
 inj    85
0.4
s < 0.3 psec
t
0.2

0
0
5
10
15
20
Delay Arm Position (psec)
Courtesy of S. Anderson / LLNL
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Preliminary Results Consistent with
Simulation
Simulated Pulse Length Vs
Injection Phase
3
HOMDYN Simulation
Measurement
2.5
E CTR 
1.5
7º FWHM

t
s (psec)
2
1
0.5
0
-100
-80
-60
-40
-20
0
20
40
Phase wrt Peak Acceleration (degrees)
Courtesy of S. Anderson / LLNL
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Q2
st
I
SPARC - Phase 2
X band structure
RF-Gun
RF compressor
SLAC structure
SLAC structure
Longitudinal emittance compensation via
4th harmonic decelerating section (B. Spataro)
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Performances @ full compression
I
T
Longitudinal phase space distribution s taken at different tim es throughout
the compressor for the case of total compression.
Beam current (solid lin e, left scale, in A) and energy evolution (dashed lin e,
righ t scale, in MeV) through a 500 MeV Linac with impl ementation of a RF
rectilin ear compressor and a 3rd harmoni c corrector.
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Performances @ full compression
40
2
35
1.5
I
z
25
.
mm]
30
1
15
10
/
20
n
sr
0.5
/
5
0
0
0
5
10
15
20
25
z [m]
Energy spread in % (dotted line, right scale) and longitud inal emitt ance in
keV.mm (solid l ine, left scale)
Capri, 3 Giugno 2003
Rms beam envelope in mm (dotted lin e, left scale) , rms normalized
transverse emittance in mm.mrad (solid l ine, right scale) and beam peak
current in A (solid l ine, right scale) along the Lin ac. The r.h.s. diagram
shows the details of the upp er one along th e first 3 m of RF gun, drift, 3rd
harmonic structure (from z=1.2 to z=1.28) and RF compressor (from z=1.4
to z=4.4)
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Application to SPARX (M. Ferrario)
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
SPARC Building Complex
Bunker open for implementation of future beam experiments
with additional beam lines
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
SPARC-I
Laser layout
10 nJ
800 nm IR
10 ps flat-top
266 nm UV
Larger Laser Pulse
Energy needed for
TW Photon Beams
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Upgrade of SPARC Laser to TW Power
Level: third stage of amplification to reach
0.5-1 J energy per pulse ( P > 10 TW )
Mode-locked
femtosecond
Ti:sapphire
oscillator
10 Hz, SH, 1 J
Flashlamp pumped
Nd:YAG laser
Stretcher
To the
Compressor
FR
IRIS
IRIS
BD
IRIS
IRIS
73゜
Courtesy of F. Sakai
Capri, 3 Giugno 2003
Regenerative Amplifier
5-pass master Amplifier
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Pulse
Stretcher
Oscillator
Multi-Pass
Amplifier
Regenerative
Amplifier
Pulse Compressor
under vacuum
Courtesy of F. Sakai
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Two additional beam lines at SPARC for plasma
acceleration and monochromatic X-ray beams
100 fs synchr.
Ti:Sa multi-TW
Laser System
1 J, 10 ps gaus
20 mJ, 10 ps flat top
500 J
Compr.1
2 nC, 10 ps*
J, 100 fs gaus
20 pC, 20 fs$
*n=2 m, s=50 m
1 nC, 10 ps, n=1 m
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
$
n=0.2
m, s=10 m
All Optical Injectors (Plasma Guns) vs
External Injection
L.I.L.AC scheme,
D. Umstadter
Plasma wavelength 10-100 m
Local Wave-Breaking induced by second (synchronized!) laser pulse
Captures background plasma electrons locally into the accelerating bucket (D. Giulietti)
<R> [mm]
enx [mmmrad]
Tfin = 360 MeV
20 fs, 1 kA, 6% en. spread
20
1.5
15
1
10
0.5
5
0
0
0
0.1
0.2
0.3
0.4
Z [m]
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
enx [mmmrad]
External Injection in SPARC
HOMDYN (M.Ferrario)
<R> [mm]
2
p = 300 m
sp= 100 m
Eacc = 3 GV/m
Compact Sources of Monochromatic X-rays
based on Relativistic Thomson back-scattering
X las / 42((1-cosY)/2)
las = 0.8 m
 =80 (40 MeV)
X =0.32 Å, 37 keV
NX  T f
N  N h
e
2
s coll
 T  710 29 m2
N X  2 10 9 /11

f  10Hz, N _  1010 , Nh  1018 , s coll  50, 5m
e
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”

Non-invasive Coronaric Angiography
Dynamic IVCAG (Intravenous Coronary Arteriography) using monochromatic
X-rays produced by Synchrotron Radiation and monochromators was clinically
tested at KEK-AR and Tsukuba University, obtaining clear dynamic images (33
shots/s) of the coronary artery, with 37 keV X-rays , 1011 photons/s generated by
an undulator at the AR ring (intravenous contrast agent applied).
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Mammography with Mono-chromatic X-Rays
Mammography images of adenoca rcinoma. (a) conventional mammogr.; (b)
monochromatic beam at 22.2 keV; (c) phase con trasst image; (d) histological section.
The con strast (sens iti vit y to tis sue density variations ) goe s from 8% to 0.1%, whil e the
spatial r esolution go es from 0,15 -0,3 mm to 0.01-0.015 mm. This means the capabilit y to
detect a tumor 30 tim es small er in volume, i.e. a 2 yea r earli er detection o f the tumor.
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Experiments world-wide on ComptonBackscattering for Monochromantic X-rays
Sumitomo-Festa (S-band, medical)
Univ. of Tokyo - NERL (S-band, medical)
NIRS - Univ. of Tokyo - KEK (X-band, medical)
SLAC (X-band, medical)
Brookhaven ATF (S-band, by-product in laser acceleration)
Livermore (S-band, material studies, nuclear weapons)
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Sumitomo - Festa Collab. (Tokyo)
Measured spatial profile of the scattered X-rays
(The electron beam is in the plane of the laser polarization)
X
Y
70mm
(B)
**The lines represent the results of the theoretic analysis**
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Spectral Distributions
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
CONCLUSIONS
• SPARC is aimed at delivering within 3 years a top brightness
electron beam (Ph. 1)
• Velocity Bunching will ultimately allow to reach
unprecedented quality beams in a compact system (200 MeV)
• SPARC has the chance to become an advanced facility in the
international scenario to conduct frontier beam physics (High
Gradient Acceleration and Advanced X-ray Beams)
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Innovative Concepts / Components in SPARC
• Use of Shaped Laser Pulses (minimize space charge non-linearities)
• Implementation of Ferrario Working Point in an optimized integrated photoinjector (proper phase tuning of emittance oscillations)
• Applying Velocity Bunching with Emittance Preservation (increasing peak
current at no expense of transverse emittance)
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
NEW CONCEPTS
Velocity Bunching in Photoinjectors
RF Compression during Acceleration
•
Rectilinear Compression (no Coherent Synch. Radiation effects) based on longitudinal
focusing in slow RF waves
•
Alternative option of bunch compression  high brightness sub-ps beams (as
needed by X-Ray SASE Fel’s)
•
Performed at low energy (10-80 MeV), fully integrated into the emittance correction
process (for maximum brightness)
LS and M. Ferrario, AIP 581 (2001) 87
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
From Thermoionic Injectors to Laser-Driven RF
Photo-Injectors : the Quest for Beam Brightness
Thermoionic Injectors operate in a quasi-steady state regime at low DC field
amplitudes - the beam has to be manipulated by bunchers to get down to the
ps time scale - this causes a severe emittance grow  Integration of
emission process into the bunching action of RF accelerating field
 RF Photo-Injectors Hera
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Emittance and brightness scaling
n
1
mm.mrad
0.8
S-band
0.6
L-band
0.4
0.2
X-band
0.2
0.4
0.6
0.8
Q
Bn
1.2
1
1.2
[nC]
1400
1200
S-band
1000
A/mm2mrad2
1
800
600
400
200
0
Capri, 3 Giugno 2003
L-band
0.2
0.4
0.6
0.8
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Q
[nC]
Achieving Uniform Bunch Distributions
using Flat-Top Laser Pulses @ Sumitomo SHI + FESTA
Temporal distributions of shaped UV laser pulses
by a X-ray streak camera
Gaussian pulse shape
Square pulse shape
The flatness of square-shaped laser pulse:
5~25% @ 4~14 ps FWHM
The fluctuation of shaped pulse length:
7% (pulse-to-pulse)@both shapes
Capri, 3 Giugno 2003
Courtesy of F. Sakai
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Achieving Record Emittances @ Sumitomo SHI + FESTA
Emittance measurements
for gaussian and square laser pulse shapes
Laser pulse length: 9ps FWHM
Courtesy of F. Sakai
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Thermoionic Injectors
LIMITATIONS
Cathode Emissivity J < 20 A/cm2

1 nC over 20 ps  scat > 9 mm
Diode Saturation

Child-Langmuir Law I = kV3/2
V=100 kV I=15 A with k=5.10-7

Field limited
MATURE and CONSOLIDATED TECHNOLOGY
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Radio-Frequency Photo-Injectors
LIMITATIONS
Transverse plasma oscillations
UCLA/SLAC/BNL
S-band next gen. RF Gun

Time dependent space charge effects
dilution of projected emittance
Photocathode and/or laser disuniform.
h

Space charge field non-linearities
dilution of slice emittance
Temperature emittance @ photocath.
Mature but non Consolidated Technology
Stability , repetibility , ease of tuning
Capri, 3 Giugno 2003
PROBLEMS
Space and Time Jitters
Laser beam quality
Challenging Diagnostics (sub-ps)
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Plasma Guns: simulations results*
(ongoing exp. @ LBL and Univ. of Michigan)
very sensitive to injection phase
particle momentum vs. time
Q=10 pC st=20 fs
sE=5%
n=5 m
Bn=1.5.1013
- Brightness comparable to RF Photo-Injectors
- fs bunches fully sinchronized to the laser
- unproven technology
- beam physics (in plasma) still to be explored
* T. Katsouleas et al., PRE 57 (1998) 5920
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Non-invasive Coronaric Angiography
1
2
Boone JM, Seibert JA. A Figure of Merit Comparis on between
Brems strahlung and Monoen ergetic X-ray Sources for Ang iogr aphy. Journal
of X-ray Science and Techno logy . 4:334-345, 1994.
Carroll FE, Waters JW, Price RR, Brau CA, Roos CF, Tolk NH, Pickens DR,
Stephens WH. Nearmonochro matic x-ray beams produced by the free electron
laser and Co mpton ba ckscatter. Inves t Radiol 25:465 -471, 1990.
"Monochromatic X Rays are capab le of delivering the same immage quality at about
half the radiation dose to the patient compared to conventional x rays tubes"
Corona ric Angiog raphy canno t be app li ed nowaday s as a mass screening diagnos tics
because of the h igh mortalit y ris k associa ted wit h the intra-artery catheter insertion: it is
considered a high risk (0.23% mortalit y, 2.2% patie nt damage ) inv asive diagnos tics.
Mono -chromatic X-ray based non-inv asive diagnos tics would all ow a population
preven tive screening of coronar ic stenos is, whic h is responsible for most of cardiovascular diseases, that in turn represent the highe st cause of mortalit y in western
coun tries.
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Experimental Results(Phase-I)
A ps electron beam
Energy:
14 MeV
Bunch charge:
0.5 nC
Pulse length:
3 ps(rms)
Focused beam size: 100 m(rms)
Pointing stability: 6 m (rms)
Time jitter:
1.4ps (rms)
between e- bunch and fs laser pulse
A fs laser beam
Wavelength:
Pulse energy:
Pulse length:
Focused beam size:
Capri, 3 Giugno 2003
800nm
85mJ/pulse
100fs(rms)
20[email protected]
108[email protected]
A X-ray beam
With the 0o-collision
X-ray energy:
Pulse length (calc.):
Intensity:
Intensity fluctuation:
4.6keV(peak)
3ps(rms),
1.5x105/pulse
10%
With the 90o-collision
X-ray energy:
Pulse length (calc.):
Intensity:
Intensity fluctuation:
2.3keV(peak)
270fs(rms),
1.4x104/pulse
25%
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Next Steps in Sumitomo-Festa Experiment
The spatial profile of a 270fs-long X-ray pulse with a peak energy of
2.3keV was measured in 90o Compton scattering as a function of the
laser polarization, and compared with the theoretical analysis.
The number of X-ray photons generated was obtained to be 1.4x104/pulse.
The stability of the X-ray intensity was measured to be 25%(rms).
Experimental Plan(Phase-II):
High-energy X-rays: >30keV
increasing the accelerated electron energy: >40MeV
High-intensity X-rays: >1010photons/s
Multi-bunch electron generation
1J femtosecond laser with multi-collision
High-stability X-rays:
A precise optical timing synchronization
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Sumitomo - Festa Collab. (Tokyo)
RF Timing
Synchronizer
TW Ti:Sapphire Laser
Remote Controlled
Mirror
Photocathode
RF Gun
Compton
Chamber
Linac
X-ray
Detectors
Beam Dump
8m
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
TW femtosecond Ti:Sapphire laser
3.6m x 1.5m
BD
PM
IRIS
Pulse
Compressor
G1
IRIS
23°
37°
56. 95°
BD
PM
IRIS
73゜
Compton
chamber
IRIS
FR
BD
BD
[Main Specifications]
pulse energy
100 mJ
pulse width
100 fs
focused beam size
50 m
pointing stability
±5 rad
pulse repetition rate
10 Hz
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
1Terawatt Ti:sapphire laser system
Mode-locked
femtosecond
Ti:sapphire
oscillator
10 Hz, SH, 1 J
Flashlamp pumped
Nd:YAG laser
Stretcher
To the
Compressor
FR
IRIS
IRIS
BD
IRIS
IRIS
73゜
Regenerative Amplifier
Capri, 3 Giugno 2003
5-pass master Amplifier
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Linearity of X-ray Intensity
vs. Laser Energy
Stability of X-ray Intensity
25% (rms)
within 10 min.
**The results observed in 90o collision**
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
X-ray Imaging Measurement
Window
Optical Lens
( f=100mm )
X-rays
ICCD Camera
(Gate time: 10ns)
MCP
Capri, 3 Giugno 2003
Phosphor Screen
(10ns,410nm)
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
90-degree laser-Compton scatterings
between a relativistic electron beam and a linear-polarized laser beam
Laser photons
electrons
Laser photons
electrons
Scattered X-rays
Scattered X-rays
(A)
(B)
(A)the electron beam is in the plane of the laser polarization.
(B)the electron beam is perpendicular to the plane of the laser polarization.
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Anticipated Performances of
Univ. of Tokyo - NERL experiment
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Pulse
Stretcher
Multi-pass
Amplifier
Regenerative
Oscilla tor
Amplifier
Pulse
Compressor
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
X-band advanced protoype
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
Capri, 3 Giugno 2003
“ Fisica e Tecnologia degli Acceleratori e Tecniche Correlate ”
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