Transcript LOA - CEA-Irfu

Laser plasma accelerator :
towards a compact e- and p- beam
Victor Malka
Faisceau laser
Laboratoire LOA, ENSTA - École Polytechnique,
France
http://wwwy.ensta.fr/~loa/SPL/index.html
Faisceau laser
Faisceau d’électrons
DAPNIA, CEA Saclay, 4 Avril (2005)
LOA
Faisceau de protons
ELF Laser group
F. Burgy
B. Mercier
J.Ph. Rousseau
Collaborators
VLPL
S. Kiselev
A. Pukhov
SPL
Particle group
E. D’humière
Y. Glinec
J. Faure
M. Manclossi
A. Tafo
B. J.J. Santos
V. Malka
CEA/DAM Ile-de-France, France
E. Lefebvre (simulations)
T. Hosokai University of Tokyo, Japan
With the support of EEC/CARE/Phin project
LOA
Outline
• Motivations
• Excitation of relativistic electron plasma waves
• e-beam : physical process and recent results
• p-beam : physical process and recent results
• Applications for Society
• Benefits for Science.
• Conclusion
LOA
Motivations
Classical accelerator limitations
E-field max ≈ few 10 MeV /meter (Breakdown)
R>Rmin Synchrotron radiation
Energy
= Length
Circle road
LEP at CERN
27 km
≈
new techniques
LOA
= $$$
PARIS
31 km
Why use a Plasma ?
Motivations
• Superconducting RF-Cavities : Ez = few 10 MV/m
• Plasma is an Ionized Medium
High Electric Fields
Ez ~ w p ~ ne
for 1 % Density Perturbation at 1017 cc-1
for 100 % Density Perturbation at 1019 cc-1
Tajima&Dawson, PRL79
LOA
0.3 GV/m
300 GV/m
Motivations
How to excite Relativistic Plasma waves?
(i) The laser wake field
F≈-grad I
Electron density perturbation
Laser pulse
Phase velocity
v vfepw=vg
=> close to c
Analogy with a boat
laser
$$$$
 laser≈ Tp / 2
=>Short laser pulse
laser≈ 200 fs for ne=1017cm-3
Optical demonstration :
Hamster et al. PRL 93: THz measurements
Marques et al. PRL 96: Spectroscopy in the time domain
Siders et al. PRL 96 : Spectroscopy in the time domain
LOA
Motivations
How to excite Relativistic Plasma waves?
(ii) The laser beat waves
F≈-grad I
k
k2
Laser envelop modulation
Train of short resonant pulses
$$$$!
1-2 = p
Linear growth :
d(t)=1/4a1a2wpt
=>Homogenous plasmas
Saturation : relativistic, ion
motion
Optical demonstration by Thomson scattering :
Clayton et al. PRL 1985,Amiranoff et al. PRL 1992,, Dangor et al. Phys. Scrypta 1990
Chen, Introduction to plasma physics and controlled fusion, 2nd Edition, Vol.1, (1984)
LOA
Motivations
Analogy electron/surfer
electron
t1
t2
t3
ge > > gf > > 1
Emax=2(d n/n) gf2 mc 2
L
Analogy:
LOA
Deph.
= l p gf 2
=> Emax (MeV)=( d n/n)(nc/n e)
=>L
deph. =(l0/2)(n c
/n e)
3/2
Motivations
LOA
Motivations
Injected electrons acceleration with laser :
Wake field , Beat wave
Few MeV gain
Laser
Injected electrons
Few MeV
LOA
LULI/LPNHE/LPGP/LSI/IC
Motivations
600
2000
500
1500
400
300
1000
d = 1,6%
Theory
Electrons number experiment
Electron Acceleration : LBWF
Electron spectra indicate an Efield of ≈ 0.7 GV/m
200
500
100
0
3,3
3,4
3,5
3,6
3,7
3,8
3,9
0
Energy (MeV)
g  =
LOA
100 ,
ge
= 6 , s laser = 40 µm , se = 40 µm , divergence = 10 mrad
Electron gain demonstration Few MeV’s:
Kitagawa et al. PRL 1992,Clayton et al. PRL 1993,N. A. Ebrahim et al.,
J. Appl. Phys.1994, Amiranoff et al. PRL 1995
LULI/LPNHE/LPGP/LSI/IC
Wakefield : Acceleration in 1.5 GV/m
The 3-MeV electrons are accelerated up to ≈ 4.5 MeV
Number of electrons
1000
Noise due to scattered electrons
100
10
1
3.00 3.50 4.00 4.50 5.00 5.50 6.00
Energy (MeV)
2.5 J, 350 fs, 1017W/cm2, 0.5 mbar He
Amiranoff et al. PRL 1998
LOA
e-beam
Electron beam Generation in Underdense Plasmas
Plasma
Laser
Electron Beam
Gas-Jet
Nozzle
LOA
How to generate an electron beam?
e-beam
(i) Self-modulated Laser Wakefield Scheme
c >>lp
Andreev et al. JETP92, Antonsen & Mora PRL92, Sprangle et al. PRL 92
excites
if
enhances
Pc(GW) = 17 02/p2
Short Pulse
LOA
Wavebreaking
then
Modena et al., Nature (1995)
Energetic Electrons
e-beam
wave breaking : from waves to particles
LOA
Review of some Former Experiments on
Electron Generation
Lab
Year
EL
RAL
1995
50 J 20 min
44 MeV
1998
50 J 20 min
100 MeV
1997
5 J 5 min
30 MeV
MPQ 1999
0.2 J 10 Hz
10 MeV
LOA 2001
1 J 10 Hz
200 MeV
NRL
Rate
Large scale, energetic laser, with low repetition rate
LOA
Ee
Salle Jaune Laser
CPA : G. Mourou
Oscillator : 2 nJ, 15 fs
Stretcher : 500 pJ, 400 ps
8-pass pre-Amp. : 2 mJ
Nd:YAG : 10 J
5-pass Amp. :
200 mJ
4-pass, Cryo. cooled Amp. :
< 3.5 J, 400 ps
LOA
2m
After Compression :
1 J, 30 fs, 0.8 mm,
10 Hz, 10 -7
e-beam
Neutral profil density measurements :
the gas jet’s lab
z
z
2 mill.
2 mill.
2 mill. rayon
5
0
16
5
1
Densité de neutre (cm-3)
-3
18
Density (10
cm )
Phase (radians)
10
2 mill. rayon
1 1019
81018
61018
41018
21018
0
-4 -3 -2 -1 0 1 2 3 4
Rayon (mm)
LOA
V. Malka et al., RSI (2000)
e-beam
Gas Jet Nozzle Design
For laser plasma studies
LOA
N ext
D exit
mm
L opt
mm
Mach
exit
19
1
2
6
3.5
18 x 10
19
1
3
7
4.75
7.5 x 10
19
1
5
10
7
2.7 x 10
19
1
10
15
10
0.75 x 10
D exit
mm
L opt
mm
Mach
exit
0.5
1
4
3.3
16 x 10
0.5
2
5
5.5
4.5 x 10
0.5
3
5
6.2
2.1 x 10
0.5
5
7
9.5
0.7 x 10
S. Semushin & V. Malka et al., RSI (2001)
N ext
cm-3
D crit
mm
cm-3
D crit
mm
19
19
19
19
F/6
Tunable electron beam : temperature
Electrons are accelerated by epw
# electrons/MeV/sr
100
10
9
10
Teff=8.1 MeV
8
max
Teff=2.6MeV
E
10
7
10
detection threshold
6
10
(MeV)
10
0
10
20 30 40 50 60 70
W (MeV)
10
19
10
20
10
-3
n (cm )
e
dn
E max = 4g mec
n
2
p
V. Malka et al., PoP (2001)
LOA
2
f/18 experiment
e-beam
10
10
10
8
10
7
10
6
10
75
50
25
Detection Threshold
5
10
DE/E=10%
100
9
Charge (pC)
Number of electron (/MeV/sr)
Recent results and beam charge value
0
50 100 150 200
Energy (MeV)
0
20
50
100
Energy (MeV)
V. Malka et al., Science, 298, 1596 (2002)
LOA
200
e-beam
Low Normalized Emittance
Emittance is indeed comparable with todays Accelerators
n = ~ 3  mm mrad
x (mrad)
0.05
Ee- = ~ 20 MeV
0
en = ~ 32  mm mrad
-0.05
- 0.5
-0.25
0
x (mm)
0.25
n (  mm mrad)
Ee- = ~ 55 MeV
40
20
0.5
20
60
Electron Energy (MeV)
S. Fritzler et al., PRL 04
LOA
40
e-beam
Forced Laser Wake Field :
c  lp/2 and P>Pc
Electron bunch
laser
Electron density perturbation
ne/n0-1
Electric field
Electron density
0
advantages of short laser pulses
V. Malka, Europhysics news, April 2004
LOA
laser
SMLWF : Linear regime / FLWF : Non linear regime
SMLWF : Multiple e- bunches / FLWF Single e- bunch
Electron bunch
laser
Electron density perturbation
ne/n0-1
Electric field
Electron bunches
Electric field
0
V. Malka, Journal Société Française de Physique, April 2004
LOA
laser
One stage LPA
Quasi-Monoenergetic Electron Beams
In homogenous plasma
VLPL
Time evolution of electron spectrum
Ne / MeV
1 109
t=750
t=650
20
t=850
t=550
Y/l
5 108
20
-20
t=450
65
0
Z/l 70
-2
0
X/l
0
t=350
0
200
400
E, MeV
A.Pukhov & J.Meyer-ter-Vehn, Appl. Phys. B, 74, p.355 (2002)
LOA
monoenergetic
electron beam
Experimental Setup : single shot
measurement
LOA
Qualité spatiale du faisceau d’électrons:
Recent results on e-beam quality improvements
Dépend fortement de la propagation laser
100 bars
20 bars
60 bars
40 bars
15 bars
10 bars
Divergence
< 6 mrad
LOA
Recent results on e-beam :
From Mono to maxwellian spectra
Electron density scan
LOA
Recent results on e-beam :
Energy distribution improvements
e-beam
Charge in [150-190] MeV : (500 ±200) pC
Experiment
PIC
LOA
J. Faure et al., Nature ,30 september Nature 2004
C. Geddes et al., S. Mangles et al. , in Nature this week too
RAL, LBNL and in Tokyo
e-beam
FLWF/BR : Beam charge improvement
FLWF
Bubble
regime
DE/E=10%
Charge (pC)
500
0
LOA
20
50
100
Energy (MeV)
200
very hot topic !
state of art
Other recent results RAL & LBNL
also to be published tomorrow in Nature!
50 pC
300 pC
RAL
LOA
&
LBNL
e-beam
J. Faure et al., C. Geddes et al., S. Mangles et al. ,
in Nature 30 septembre 2004
LOA
Front and back acceleration mechanisms
Peak energy scales as : EM ~ (IL×l)1/2
LOA
Large Laser results : Vulcan laser
Behind the target –
“straight through”
direction
5 cm
50J:1ps & 1shot/20min.
BACK
In front of target
– “blow-off”
direction
5 cm
5 cm
LOA
FRONT
5 cm
p-beam
Motivation of ultra short laser pulses
• large lasers:
>1012 protons, energies up to 50 MeV
lasers ~1 ps, > 100 J 1 shot every 40 minutes
• the key parameter : laser intensity
• Emax (protons)  (Il2)1/2
I = E/(S)
• I constant: reducing E and 
• Titane saphir laser technology:
table top, 2 J in 30 fs, 10 tirs per second !
LOA
p-beam
Proton Beam Characteristics
Energy
Aluminum Target
Plastic Target
In collaboration with K. Ledingham and P. Mc Kenna
LOA
Collimation
Simulations PIC 2D
6 nc
6 nc
Front and back acceleration
LOA
6 nc
Proton beam quality n < .004 mm-mrad
Short Pulse
Laser
10 mm
Au grating
60 mm thick
200 lines/mm
Laser accelerated
protons
Film
Detector
Stack
(70 mm from
target)
10
T. Cowan, J. Fuchs. H. Ruhl et al.,
Phys. Rev. Lett. 92, 204801
(2004).
Experiment done at LULI.
5
8 MeV layer
0
-5
-10
-10 -5 0
5 10
Angle (degrees)
LOA
Extrapolations with PIC simulations
Target : pre-plasma of 7 µm, plasma thickness of 1 µm
Laser: 50 fs, 50 J (PW), I=1021 W/cm2
Maximum proton energy (MeV)
400
Laser PW ultra-short:
>1011 protons up to 300 MeV
350
21
60fs, 2.10 W/cm
300
250
200
150
100
50
0
0
1
2
3
4
Thickness (micron)
5
• Needs to develop a PW 10Hz,
30 fs laser.
E. Fourkal et al. Medical physics (2002)
V. Malka et al., Med. Phys. 31, 6 June (2004)
LOA
2
Protontherapy: motivations
tumour
70-200
MeV
Protons
Dose
Nb p+
Depth
LOA
..
E1<E2
Energy
On the use of a broad spectra :
Requiered Dose
Theoretical Spectra
Needed Spectra
(simulations)
Nb p+
depth
Energy
 Energy and particle selectors
mask
collimator
source
p+
patient
eB
Doses
de 10aine de Gy/min*
bloc
B
B
Enough for protontherapy
E. Fourkal et al, Med. Phys. 30, p. 1660 (2003),
LOA
Protontherapie: motivations
100
80
Bragg Peak
X Ray
8 MeV
Protons
230MeV
60
40
20 Electrons
20MeV
0
0
10
5
15
20
25
30 32
Depth in tissue (cm)
• Lateral precision
Dose normalisée (%)
Relative dose
• Pic de Bragg: precision
longitudinal
100
Distribution 1D
0
-10
10
0
Distance au point de référence (cm)
But still 99% of radiotherapy is done with g
LOA
Protontherapy: accelerators
• Synchrotron (Loma Linda) :
• max p energy : 250 MeV
• period : 2.2 s
• size : 12 m
LOA
• Cyclotron (IBA-NPTC) :
• max p energy : 250 MeV
• pulse rate : CW
• power: 400 KW
• size : 4 m (diameter)
• weight : 220 tons
Applications
The laser based proton therapy ?
Challenges:
Developpe PW compact laser
- Stability of the laser
- Reduced the prepulse
to obtain protons in 250-300 MeV energy range
to obtain enough protons at those energies in less than few minutes
Questions:
- Stability of the proton source?
Potentiels advantages :
- New fields of research : biological, chemistry aspect
LOA
- Cost: could be 5 times cheaper ? (Laser PW < few M€ and
smaller radio-protection area)
Applications
PET Isotope Production
11B(p,n)11C
18O(p,n)18F
Activation
Target
11B
18O
T1/2 = 20,4 min,
T1/2 = 109,7 min,
LOA Laser
at 10 Hz
(mCi)
0,4
0,08
Q-value = 2,8 MeV
Q-value = 2,4 MeV
LOA Laser
at 1 kHz
(mCi)
36,2
7,9
Cyclotron
(mCi)
20
20
Irradiation Time : 30 min, Activation Target : 0,24 g/cm²
Difficult to compete with current accelerators performances:
Cyclotron : 100 mA, laser < 1mA
1Gy at LOA? See Emmanuel poster
S. Fritzler et al., Appl. Phys. Lett. 2003
LOA
17 October 2003
PHILIP BALL
Lasers may make PET scans cheaper
Radioactive materials for medical imaging produced at lower cost.
PET scans rely on the radioactive decay
of isotopes.
PET scanning could become cheaper and
more widespread, thanks to a new benchtop way to produce rare radioactive
atoms1. Current methods of making
radioisotopes render the medical-imaging
technique cumbersome and expensive.
The problem is that these isotopes decay
quickly - within minutes or hours. So they
have to be made at the same place and
time as the scan, by particle accelerators
that fire beams of protons at other
materials. "Due to the size, cost and
shielding required for such installations,
PET is limited to only a few facilities,"
explains Victor Malka of the École
Polytechnique in Palaiseau
© SPL
S. Fritzler et al., Appl. Phys. Lett. 2003
LOA
PET delivers volume
information of tumours :
Protontherapy
Taking advantage of
ballistic characteristics
of quasi-monocinetic
proton beam
LOA
Relevance of laser plasma approach
for high energy physics > TeV
6
Define in collaboration with
high energy physicists the
requierement
for
their
experiments
(particles,
charge, stability current,
luminance,reproducibility).
10
Maximale Electrons Energy (MeV)
RF technology
5
10
4
10
1000
RAL 
LOA 
RAL  LOA
 *LLNL
UCLAKEK
100
10
ILE ¤
Define schemes, cost and
compare
to
conventional
approach
(present
and
expected)
Single stage or multi stage?
1
1930 1940 1950 1960 1970 1980 1990 2000 2010 Laser or e-beam ?
LULI  
Years
LOA
Conclusion and future of laser plasma accelerator
•Laser particle acceleration has been demonstrated
•E-fields up to 1000 GV/m
•Good quality
•Quasi monoenergetic e-beam are produced
•Energy gains of 1 MeV to 200 MeV
•Electron sources up to ≈ 1 GeV (nC, <100fs) = XFEL
•For high energy the requierements are extreme:
Luminosity : 1000 bunches/s with 1nC per bunch
at 1 TeV : =>much more than 1000*1000J/s=1MJ/s 1 MW particle :
10-100 MW laser ?
•Research related to laser technology evolution
•Lasers parameters must be flexible: 0.1J-5
fs, 30 J-30 fs, 1 MJ-1 ps ?
LOA
New Sciences
Applications and New Science
X-rays:diffraction
g-rays:radiography
Material science
Medicine
Radiotherapy
Proton-therapy
Radioisotopes PET
Radiobiology
New science on
“ultrashort phenomena”
Accelerator Physics
e beam, and p beam ?
and nuclear physics
High current
LOA
Chemistry
Radiolysis by ultra
short e or p beam
Applications
Application: high resolution g-radiography
Advantages: low divergence, point-like electron source
In collaboration with L. Le-Dain, S. Darbon from CEA Mourainvilier and DAM
LOA
g-radiography results
Applications
Higher resolution: of the order of 400 mm
measured
calculated
In collaboration with L. Le-Dain, S. Darbon from CEA Mourainvilier and DAM
LOA
Application for radiolysis :
H2O
e-
(e-s, OH., H2O2, H3O+, H2, H.)
Very important for:
• Biology
• Ionising radiations
effects
In collaboration with Y. Gauduel ‘s group
LOA
Recent results on Femtolysis :
Y. Gauduel et al., submitted at J. Phys. Chem.
LOA
The concurrence is increasing, the increase of the concurrence is increasing !!!
..
. ..
..
.
... .
. .
.. . .
.
LOA
.. ...
..