Laserplasma accelerators Status and perspectives Victor Malka LOA

Laser-plasma accelerators: Status and perspectives Victor Malka LOA, ENSTA – CNRS - École Polytechnique, 91761 Palaiseau cedex, France laser Electron beam 170 +/-20 Me. V 500 p. C 6 mrad Gas jet Journées accélérateurs, Roscoff, FRANCE , 9 -12 (2005) LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 1/38

SPL ELF Particle group Laser group F. Ewald J. Faure Y. Glinec A. Lifschitz J. J. Santos F. Burgy B. Mercier J. Ph. Rousseau Collaborators A. Pukhov, University of Dusseldorf, Germany E. Lefebvre, CEA/DAM Ile-de-France, France P. Mora, CPh. T, X, CNRS, France CARE / FP 6 LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 2/38

Classical accelerator limitations E-field max ≈ few 10 Me. V /meter (Breakdown) R>Rmin Synchrotron radiation Energy = Length = $$$ Circle road LEP at CERN 27 km ≈ PARIS New medium : the plasma LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 3/38 31 km

Why is a Plasma useful ? • Superconducting RF-Cavities : Ez = 55 MV/m • Plasma is an Ionized Medium High Electric Fields Ez ~ w p ~ ne Are Relativistic Plasma waves efficient ? Ez ~ LOA ne Ez = 0. 3 GV/m for 1 % Density Perturbation at 1017 cc-1 Ez = 300 GV/m for 100 % Density Perturbation at 1019 cc-1 Journées accélérateurs, SFP, Roscoff 05 FRANCE 4/38

How to excite Relativistic Plasma waves? The laser wake field F≈-grad I Electron density perturbation Laser pulse tlaser≈ Tp / 2 =>Short laser pulse Phase velocity vfepw=vg => close to c Analogy with a boat laser Tajima&Dawson, PRL 79 LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 5/38

Motivations How to excite Relativistic Plasma waves? (ii) The laser beat waves F≈-grad I k k 2 Laser envelop modulation Train of short resonant pulses $$$$! 1 - 2 = p Linear growth : d(t)=1/4 a 1 a 2 wpt =>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, 2 nd Edition, Vol. 1, (1984) LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 6/38

Motivations Analogy electron/surfer electron t 1 t 3 t 2 ge > > gf > > 1 Emax=2(d n/n) gf 2 mc 2 L Deph. = l p gf 2 => Emax (Me. V)=( d n/n)(nc/n e) =>L deph. =(l 0/2)(n c /n e) Analogy: LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 7/38 3/2

Motivations LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 8/38

Motivations Injected electrons acceleration with laser : Wake field , Beat wave Few Me. V gain Laser Injected electrons Few Me. V LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 9/38

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 (Me. V) g = LOA 100 , ge = 6 , s laser = 40 µm , se = 40 µm , divergence = 10 mrad Electron gain demonstration Few Me. V’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 Journées accélérateurs, SFP, Roscoff 05 FRANCE 10/38

How to generate an electron beam? Self-modulated Laser Wakefield Scheme (Andreev et al. , Sprangle et al. , Antonsen & Mora 1992) ct >> lp excites if LOA enhances Pc(GW) = 17 w 02/wp 2 Short Pulse then Wavebreaking Energetic Electrons Modena et al. , Nature 1995 Journées accélérateurs, SFP, Roscoff 05 FRANCE 11/38

Wave breaking : from waves to particles LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 12/38

Salle Jaune Laser based on CPA technique Oscillator : 2 n. J, 15 fs Stretcher : 500 p. J, 400 ps 8 -pass pre-Amp. : 2 m. J Nd: YAG : 10 J 5 -pass Amp. : 200 m. J 4 -pass, Cryo. cooled Amp. : < 3. 5 J, 400 ps LOA 2 m Journées accélérateurs, SFP, Roscoff 05 FRANCE After Compression : 1 J, 30 fs, 0. 8 mm, 10 Hz, 10 -7 13/38

The target gas jet Developed at the gas jet’s lab z z 2 mill. 5 0 LOA 2 mill. rayon Densité de neutre (cm-3) Phase (radians) 10 -3 18 Density (10 cm ) 2 mill. rayon 16 5 1 8 1018 6 1018 4 1018 2 1018 0 -4 -3 -2 -1 0 1 2 3 4 Rayon (mm) V. Malka et al. , RSI (2000) Journées accélérateurs, SFP, Roscoff 05 FRANCE 1 1019 14/38

Gas Jet Nozzle Design and improvement 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 , RSI (2001) Journées accélérateurs, SFP, Roscoff 05 FRANCE 15/38 N ext cm-3 D crit mm 19 19

F/6 Tunable electron beam : temperature Electrons are accelerated by epw Teff =2. 6 Me. V C A E detection threshold H 10 T 0 10 20 30 40 50 60 70 E S WA(Me. V) E R C IN 7 10 6 LOA N O I N E L T A R E L CE max 8 Teff=8. 1 Me. V (Me. V) 9 10 10 H T G Ne=1. 5 x 1019 cm-3 Ne=1. 5 x 1020 cm-3 10 10 E # electrons/Me. V/sr 100 10 19 10 20 -3 n (cm ) e dn E max = 4 g mec n 2 p V. Malka et al. , Po. P (2001) Journées accélérateurs, SFP, Roscoff 05 FRANCE 10 16/38 2

Interaction chamber (inside) 50 cm Laser beam electron beam LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 17/38

Summary of FLWF previous results Emittance is indeed comparable with todays Accelerators n = ~ 3 mm mrad Ee- = ~ 55 Me. V Experiments/3 D PIC simulations 10 9 10 40 8 n ( mm mrad) Number of electron (/Me. V/sr) 10 10 7 10 6 10 LOA Detection Threshold 5 10 20 0 50 100 150 Energy (Me. V) 200 20 Electron Energy (Me. V) V. Malka et al. , Science, 298, 1596 (2002) S. Fritzler et al. , PRL 04 Journées accélérateurs, SFP, Roscoff 05 FRANCE 40 18/38 60

SMLWF : Multiple e- bunches / FLWF Single e- bunch Electron bunch laser Electron density perturbation ne/n 0 -1 Electric field Electron bunches Electric field 0 fs Ps V. Malka, Europhysics news, April 2004 (Ps/fs) LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 19/38 laser

One stage LPA Quasi-Monoenergetic Electron Beams VLPL In homogenous plasma : virtual or real? Time evolution of electron spectrum Ne / Me. V 1 109 t=750 t=650 t=850 monoenergetic electron beam t=550 5 108 t=450 t=350 0 200 400 E, Me. V A. Pukhov & J. Meyer-ter-Vehn, Appl. Phys. B, 74, p. 355 (2002) LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 20/38

Experimental Setup : single shot measurement LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 21/38

Spatial quality improvements 5. 0 x 1019 cm-3 1. 0 x 1019 cm-3 3. 0 x 1019 cm-3 2. 0 x 1019 cm-3 6. 0 x 1018 cm-3 7. 5 x 1018 cm-3 Divergence = 6 mrad LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 22/38

From Mono to maxwellian spectra : the bubble regime : optimum when ct. L lp LOA V. Malka, et al. , Po. P 2005 Journées accélérateurs, SFP, Roscoff 05 FRANCE 23/38

Energy distribution improvements: The Bubble regime Charge in [150 -190] Me. V : (500 ± 200) p. C Experiment PIC Divergence = 6 mrad J. Faure et al. , LOA in Nature 30 septembre 2004 Journées accélérateurs, SFP, Roscoff 05 FRANCE 24/38

Some Applications. . . Chemistry Accelerator Physics Radiolysis Electrons and Protons generated by Laser-Plasma Interactions X-rays: diffraction Medicine medicine g-rays: radiography LOA + X ray Larmor X ray laser Journées accélérateurs, SFP, Roscoff 05 FRANCE Radiotherapy Proton-therapy PET 25/38

Ge. V acceleration in two-stages Laser Gas-Jet Laser Plasma channel Ge. V • 1 J • 10 TW • 30 fs Nozzle • 170± 20 Me. V • 30 fs • 10 mrad • 50 -150 TW • ~50 fs Density profile rc • Pulse guiding condition : Δn>1/πre rc Δn n 0 2 • Weak nonlinear effects more control : a 0 ~ 1 -2 • High quality beams : Lb <λp LOA n 0<1018 cm-3 Journées accélérateurs, SFP, Roscoff 05 FRANCE 26/38

Ge. V in low plasma density in plasma channel n 0=8 1016 cm-3, 11 J - 140 TW rc=40 μm, Δn=2 n 0 Electric field d. N/d. E(a. u. ) Electron bunch 4 8 cm L channel=4 cm 12 cm 3 2 1 0 0 400 Electron bunch 800 1200 Energy (Me. V) V. Malka et al. , to be published in Royal Society and Phil. Trans. LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 27/38

On the ultra short duration benefit fs radiolysis : H 2 O e- (e-s, OH. , H 2 O 2, H 3 O+, H 2, H. ) Very important for: • Biology • Ionising radiations effects B. Brozek-Pluska et al. , Radiation and Chemistry, 72, 149 -159 (2005) **Ar. LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 28/38

Material science: g-ray radiography High resolution radiography of dense object with a low divergence, point-like electron source In collaboration with L. Le-Dain, S. Darbon from CEA Mourainvilier and DAM LOA Glinec et al. , PRL 94 p 025003 (2005) Journées accélérateurs, SFP, Roscoff 05 FRANCE 29/38

g-radiography results 20 mm A-A' cut Cut of the object in 3 D • Spherical hollow object in tungsten with sinusoidal structures etched on the Measured Calculated Source size estimation : inner part. LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 30/38 450 um

Medical application : Radiotherapy VHE ELECTRONS LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 31/38

Radiation Therapy Photon beams are commonly used for radiation therapy Photon beam Photon dose tumor Depth in tissue LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 32/38

VHE Radiation Therapy l Reduced dose in save cells l Deep traitement l Good lateral contrast VHE dose tumor Depth in tissue LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 33/38

Dose deposition profile in water LOA Glinec et al. , Accepted to Med. Phys. In collaboration with DKFZ (Germany) Journées accélérateurs, SFP, Roscoff 05 FRANCE 34/38

The laser plasma accelerators status Laser plasma acceleration has demonstrated • charge at high energy • Quasi monoenergetic Provide e-beam with new parameters : short Provide e-beam with new parameters : high current Provide e-beam with new parameters : Collimated Compact and low cost LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 35/38 ゝ ゝ Laser plasma accelerators advantages ゝ ゝ ゝゝ ゝ • Energy gains of 1 Me. V to 200 Me. V • E-fields of 1 GV/m to 1000 GV/m • Good e-beam quality : Emittance < 3 mm. mrad

Perspectives Laser plasma accelerator: • enhance stability • electron sources up to ≈ 1 Ge. V (n. C, <1 ps): Guiding or PW class laser systems Single Stage (Pukhov, Mori) (200 TW) • Generate a tunable e-beam • applications of these electron sources • Compact XFEL LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 36/38

Next Step: Ge. V electron beams (1 stage) Total charge = 1. 1 n. C w 0 = 20 m m t = 30 fs P = 200 TW l = 0. 8 mm a 0 = 4 � � f(E) (a. u. ) 2. 5 After 5 Zr / 7. 5 mm np =1. 5 ´ 1018 cm 3 P » 10 Pc 2 � 1. 5 1 � LT » 1. 0 cm Ldp » 1. 3 cm � DE » 1. 5 Ge. V 0. 5 0 LOA 800 1200 1600 Energy (Me. V) 2000 * Gordienko et al, Po. P 2005, UCLA group Journées accélérateurs, SFP, Roscoff 05 FRANCE 37/38

A revolution is coming…one of the most evolving field in Science, a wonderful tool for academic formation . . Thanks for your attention ! LOA Journées accélérateurs, SFP, Roscoff 05 FRANCE 38/38