Electron Acceleration
at PEtawatt pARametric Laser (PEARL)
V.N.Ginzburg, E.V. Katin, E.A. Khazanov, A.V. Kirsanov, V.V. Lozhkarev, G.A. Luchinin,
A.N. Mal'shakov, M.A. Martyanov, O.V. Palashov, A.K. Poteomkin, A.M. Sergeev,
A.A. Shaykin, A.A. Soloviev, M.V., Starodubtsev, I.V. Yakovlev, V.V. Zelenogorsky
Institute of Applied Physics, Russian Academy of Science.
IAP RAS
Introduction
 PEtawatt pARametric Laser (PEARL)
 Electron acceleration: diagnostics
 Electron acceleration: results
Conclusion
IAP RAS
Introduction. Motivation
Petawatt lasers are promising for future biomedical applications
Their interactions with targets at relativistic intensities > 1019 W/cm2
result in production of hard X-Rays and Mev particles that
can be used for diagnostic and treatment
- Phase-contrast X-Ray imaging
- Isotope factories for PET
- Laser ion sources for hadron therapy
- Table-top X-FEL
- Material sciences
The underlying physics is essentially nonlinear
and put a number of problems to be studied
in the frame of theory and laboratory experiments
IAP RAS
Introduction. Laser ion sources for hadron therapy
Proton
Accelerator
Laser system
magnet
Ion beam
~30m
Laser Plasma Ion Source
（～10ｍ、 ～billion yen (~10 million $)）
Synchrotrone Ion Source
（～100ｍ、 ～10 billion yen (~100 million $)）
IAP RAS
Mamiko Nishiuchi et al, LPHYS’05
Advanced Photon Research Center
Japan Atomic Energy Research Institute
Introduction. electron acceleration.
linear accelerator
laser accelerator
50 GeV LINAC at Stanford
3 км
Laser beam
Gas jet
field ~ 10MeV/m
2мм
field ~ 100 GeV/m
IAP RAS
Introduction.
electron acceleration.
Geddes et al, Nature 431, 538 (2004)
E ~ 90 MeV
DE/E ~ 4%
Div. ~ 2 mrad
J. Faure et al., Nature 30 septembre 2004
He, H2
eIpk ~ 1018 W/cm2
10 TW, 40 fs
Bubble formation in
relativisticallyunderdense regime
ne
S 
 1
IAP RAS a 0 n c
•A.Pukhov et al, Appl Phys
B, 74, 355 (2002)
experiment 170Мэв
PIC
Introduction
PEtawatt
 PEtawatt pARametric Laser (PEARL)
PEARL
pARametric
 Electron acceleration: diagnostics
 Electron acceleration: results
Conclusion
24 J @
910 nm
43
fs
IAP RAS
Laser
PEtawatt pARametric Laser (PEARL).
Petawatt laser systems
type I
type II
type III
Gain medium
Nd:glass
Ti:sapphire
KD*P
Energy source
Nd:glass
Nd:glass
Nd:glass
Pump
no
2w Nd
2w Nd
Pump duration, ns
no
<30
1
Amplifier aperture, cm
40х40
8
40х40
Minimum duration, fs
250
25
25
Efficiency (1w Nd фс), %
80
15
10
Number of PWs from 1 kJ 1w Nd
3.5 (3)
8 (3)
4
Maximum power obtained, PW
1.3 PW
0.85 PW
0.56 PW
LLNL, 1997
JAEA 2004
IAP 2006
Diffraction grating damage threshold
IAP RAS
Ti:sapphire damage threshold
PEtawatt pARametric Laser (PEARL).
OPCPA vs CPA
Advantages of OPCPA:
 broad gain bandwidth
 high aperture
 considerable decrease in thermal loading
 significantly lower level of ASE
 very high gain
 no self-lasing
 no backscattering from a target
Disadvantages of OPCPA:
 high precision synchronization
 high quality of a pump beam
 short (1ns) pump pulse duration
IAP RAS
PEtawatt pARametric Laser (PEARL).
Physics of OPCPA. KD*P vs KDP.
0,35
KD*P bandwidth
KD P bandwidth
KD*P absorption
KDP absorption
1500
0,3
0,25
1200
1
527 nm
900

1
911 nm
-1
KD*P  DKDP

10,2
1250 nm
0,15
600
0,1
generated phase matching
300
lsignal=2lpump=1053nm
0
750
850
950
0,05
1050
1150
1250
0
1350
signal wavelength, nm
IAP RAS
ordinary wave absorbtion, cm (dots)
-1
FWHM of gain spectra, cm (lines)
1800
superbroadband
phasematching
V.V.Lozhkarev, G.I.Freidman, V.N.Ginzburg, E.A.Khazanov, О.V.Palashov,
A.M.Sergeev, I.V.Yakovlev. Laser Physics, 15, 1319 (2005).
PEtawatt pARametric Laser
(PEARL). Architecture
Cr:Forsterite
fs-laser
l=1250nm
Synchronization
system
Nd:YLF
Q-switch laser
l=1053nm
10mJ
12nc
Pulse shaper
2nJ
40 fs
1nJ
0.5 ns
Stretcher
40 fs  0.5
ns
1mJ
1.5ns
CW Yb:fiber pump
10W
l=1050…1080nm
OPA I
KD*P
50 mJ
50 fs
2 Hz
l=911nm
0.8mJ
OPA II
0.5ns
KD*P
Compressor
0.5 ns  50 fs
1J
1.5ns
Two-stage
Nd:YLF
amplifier
Nd:glass
amplifier
2J
1.5 ns
300J
1ns
2w
l=1250nm
2w
170J
1ns
OPA III
KD*P
10cm dia
l=911 nm
50 mJ
0.5 ns
38J
0.5ns
First phase
(TW level)
Compressor
0.5ns  50fs
24J
43fs
Second phase (PW level)
Freidman G., Andreev N., Ginzburg V., Katin E., Khazanov E., Lozhkarev V.,
IAP RASPalashov O., Sergeev A., Yakovlev I. Proc. SPIE, v.4630, p.135-146, 2002.
PEtawatt pARametric Laser (PEARL).
Nd:glass laser output beam
300J, 1ns
50 mrad
2.44l/D=21mrad
10
20
30
40
50
60
90мм
70
0
IAP RAS
10
20
30
40
50
60
70
PEtawatt pARametric Laser (PEARL).
Energy characteristics of final OPCPA
Efficiency, %
38 J
40
35
35
Pulse energy. J
2.44l/D=21mrad
5
25mrad
10
15
30
30
Output pulse energy, J
40
20
Efficiency, %
25
25
25
30
35
20
20
15
15
10
10
40
45
20
40
5
5
60
80
0
0
100
120
0
30
60
90
120
150
Pump pulse energy, J
180
140
160
180
200
IAP RAS
220
5
10
15
20
25
30
35
40
45
PEtawatt pARametric Laser (PEARL).
Compressed 0.56 PW pulse
1
ACF experiment
ACF of 33fs FTL pulse
ACF, a.u.
0.75
0.5
0.25
0
-200
300
400
500
600
-150
-100
700
24 J /43 fs=0.56 PW
-50
0
time, fs
50
100
150
Contrast: 108 (0.5ns window)
104 (1ps window)
Lozhkarev V.V., Freidman G.I., Ginzburg V.N., Katin E.V., Khazanov E.A., Kirsanov A.V.,
Luchinin G.A., Mal'shakov A.N., Martyanov M.A., Palashov O.V., Poteomkin A.K., Sergeev A.M.,
Shaykin A.A., Yakovlev I.V.
Laser Physics Letters, 4, 421-427 (2007).
IAP RAS
200
PEARL. 0,56PW.
PEtawatt pARrametric Laser
CPA vs OPCPA
laser systems
10000
Vilnius U., Lithuania
CPA
Rutherford Lab, UK
1000
laser power, TW
SIOM, China
100
Rochester, USA
LLNL , USA
10
IAP, Russia
1
LLNL , USA
Rutherford Lab, UK
0.1
ILE, Japan
0.01
JAEA, Japan
0.001
1991 1993 1995 1997 1999 2001 2003 2005 2007 2009
IAP RAS
year
SIOM, China
Texas U., USA
Sarov - IAP, Russia
Introduction
 PEtawatt pARametric Laser (PEARL)
 Electron acceleration: diagnostics
 Electron acceleration: results
Conclusion
IAP RAS
Electron acceleration: diagnostics.
The experimental setup at PEARL facility.
Energy = 10 - 15 J
Plasma density: 3×1018-3×1019cm-3
spot size = 15 mm ( ~1.5 DL)
IAP RAS Intensity
= 1020 W/cm2 (a0~7)
Focusing – f/6
Jet diam = 2, 5, 10 mm
Electron acceleration:
Gas jet interferometric diagnostics.
interferogramm
N2, 80 bar (back pressure)
mm
0
1
2
3
4
5
6
7
0
1
gas jet
33
2
3
mm
He-Ne
N2 80 bar
19
x 10
Na, 1019 cm-3
2.5
4
1
0
-1
-2
-3
-4
-5
-6
1.5
-7
N
22
11
0.5
CCD
R, mm
00
IAP RAS
0
-3
1
2
-2 -1
3
0
mm
4
1
5
2
6
3
7
Electron acceleration:
Plasma channel interferometric diagnostics.
Main characteristics of the diagnostics:
•spatial resolution
~ 4 mm
•phase distortions sensitivity ~ 50 nm (l/20)
•time resolution
~ 100 fs
(because of optics in diagnostic channel)
shift
interference
The constructed optical scheme
also can be used to obtain a shadowgram
of the plasma channel.
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Electron acceleration:
1mm
Plasma channel
interferometric diagnostics.
Probe pulse
Pump pulse
IAP RAS
To interferometer
Electron acceleration:
Thomson scattering
diagnostics.
CCD camera
placed upper the nozzle
CCD
eНе
IAP RAS
2 mm
Introduction
 PEtawatt pARametric Laser (PEARL)
 Electron acceleration: diagnostics
 Electron acceleration: results
Conclusion
IAP RAS
Electron acceleration:
Electron
spectra diagnostics.
The main problem: angular dispersion
of electron bunches trajectories.
A solution is to use a couple of scintillators.
The use of two-screen electron spectrometer
allows us to take into account the angular
dispersion of generated electron bunches
and hence significantly increase the accuracy
2.5mrad
of the spectrum measurements for our setup.
24
Electron acceleration: Electron spectra diagnostics.
e- bunch angle = -0.011
angular spectra = 4,6 mrad
W = 260 MeV (20 MeV)
dW = 18 MeV (10 MeV )
charge = 18 pC
IAP RAS
-20 MeV
+20MeV
Electron acceleration: Electron spectra diagnostics.
e- banch angle = -0.011
angular spectra =
2,5 mrad X4.5 mrad
W = 190 MeV
dW = <10 MeV
charge = 11 pC
IAP RAS
Electron acceleration:
take into account
scintillator scattering .
gas
jet
optical
beam
nozzl
e
16
mrad
12
alpha2 - alpha1
8
alpha1
alpha2
4
MeV
Экспоненциальный
(alpha2 - alpha1)
0
0
IAP RAS
50
100
150
200
250
Electron acceleration: Electron spectra diagnostics.
dW=5
e- banch angle = -0.011
angular spectra =
2,5 mrad X4.5 mrad
W = 190 MeV
dW = <10 MeV
charge = 11 pC
IAP RAS
dW=15
Electron
acceleration:
spectra diagnostics.
120 pC
109MeV
W ~ 100 MeV
charge ~ 200 pC
Plasma density:
3×1018 - 3×1019cm-3
200 pC
102MeV
80 pC
97MeV
Energy = 10 - 15 J
Focusing – f/6
spot size = 15 mm (~1.6 DL)
Intensity 1020 W/cm2 (a0~7)
IAP RAS Jet diam = 2, 5, 10 mm
Electron
acceleration:
spectra
diagnostics.
W = 150 – 250 MeV
charge = 10 – 25 pC
Plasma density:
3×1018-3×1019cm-3
Energy = 10 - 15 J
Focusing – f/15
spot size 27 mm (~1.4 DL)
Intensity 1019 W/cm2 (a0~2)
Jet diameter = 10 mm
IAP RAS
2.44l/D
=21mra
d
Electron acceleration experiments in IAP RAS
W=15J, τ=45fs, d=15μm, I=1.0×1020W/cm2, λ=0.91 μm, a0=9
Numerical simulation: ponderomotive PIC code (I. Kostyukov)
10 17см-3
10 18см-3
10 19см-3
IAP RAS
Conclusions
experiments on PEARL
facility in the Institute
of Applied Physics showed:
 150-250 MeV electrons
(+/- 10%, 2mrad, 20 pC, 1GeV/cm)
 50-100 MeV electrons
(+/- 15%,
5mrad,
200 pC )
IAP RAS
Electrons acceleration :
What we may/must do.
1
0.9
0.8
0.7
Laser beam
0.6
0.5
0.4
0.3
0.2
0.1
10
15
20
25
30
IAP RAS
35
40
45
50
0
Gas jet
IAP RAS
IAP RAS
20
25
30
35
40
20
30
40
50
60
70
80
90
mm
0
10
20
30
40
50
60
70
0
20
40
60
mm
80
100
36
Характеристики пучка в фокусе
50 мкм
E = 3.5 Дж
τ = 60 фс
I = 8.5х1018 Вт/см2
a 0  8 . 6  10
 10
8.5 x
1018 Вт/cм2
4.25 x
1018 Вт/cм2
0
 l [ мкм ] I [ Вт / cм ]
2
а0 = 2.3
-50 мкм
1
50 мкм
0
e
1
b
2
k 
2
a
c  2 ab
E
0.5
IAP0RAS
Гаусс 17
Гаусс 27
Гаусс 22
Реальный
50
100
150, мкм
2b, мкм
2a, мкм
с, мкм
k
(эллип)
e (эксц)
b
a
0
2а
2b
0.5
14
23
18
1/e
17
27
22
1/e2
24
38
30
0,61
0,79
0,63
0,78
0,63
0,78
IAP RAS