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Journées accélérateurs, Roscoff, FRANCE , 9-12 (2005)

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

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Journées accélérateurs, Roscoff, FRANCE , 9-12 (2005)

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

  2. SPL ELF Particle group F. Ewald J. Faure Y. Glinec A. Lifschitz J.J. Santos Laser group F. Burgy B. Mercier J.Ph. Rousseau Collaborators • Pukhov, University of Dusseldorf, Germany E. Lefebvre,CEA/DAM Ile-de-France, France P. Mora, CPhT, X, CNRS, France CARE / FP6 Journées accélérateurs, SFP, Roscoff 05 FRANCE 2/38

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

  4. Are Relativistic Plasma waves efficient ? 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 E ~ n • Plasma is an Ionized Medium High Electric Fields z e w E ~ ~ n z p e Why is a Plasma useful ? • Superconducting RF-Cavities : Ez = 55 MV/m Journées accélérateurs, SFP, Roscoff 05 FRANCE 4/38

  5. F≈-grad I Electron density perturbation Laser pulse Phase velocity vfepw=vglaser=> close to c Analogy with a boat How to excite Relativistic Plasma waves? The laser wake field tlaser≈ Tp / 2 =>Short laser pulse Tajima&Dawson, PRL79 Journées accélérateurs, SFP, Roscoff 05 FRANCE 5/38

  6. Motivations How to excite Relativistic Plasma waves? (ii) The laser beat waves F≈-grad I $$$$! w1-w2 = wp Linear growth : d(t)=1/4a1a2wpt =>Homogenous plasmas Saturation : relativistic, ion motion k k2 Laser envelop modulation Train of short resonant pulses 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) Journées accélérateurs, SFP, Roscoff 05 FRANCE 6/38

  7. Motivations Analogy electron/surfer t t t 3 1 2 electron g g > > > > 1 f e d n/n)(n /n ) g 2 2 => E (MeV)=( d n/n) mc E =2( max f e c max l 3/2 l g =>L =( /2)(n /n ) 2 = L f deph. p Deph. c e 0 Analogy: Journées accélérateurs, SFP, Roscoff 05 FRANCE 7/38

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

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

  10. 600 2000 500 1500 400 Theory 300 1000 d = 1,6% 200 500 100 0 0 3 , 3 3 , 4 3 , 5 3 , 6 3 , 7 3 , 8 3 , 9 Energy (MeV) LULI/LPNHE/LPGP/LSI/IC Motivations Electron Acceleration : LBWF Electron spectra indicate an Efield of ≈ 0.7 GV/m Electrons number experiment g g = 100 , = 6 , = 40 µm , = 40 µm , divergence = 10 mrad s s e e w laser 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 Journées accélérateurs, SFP, Roscoff 05 FRANCE 10/38

  11. excites enhances Pc(GW) = 17 w02/wp2 Wavebreaking if then Energetic Electrons Short Pulse How to generate an electron beam? Self-modulated Laser Wakefield Scheme (Andreev et al., Sprangle et al., Antonsen & Mora 1992) ct >> lp Modena et al., Nature 1995 Journées accélérateurs, SFP, Roscoff 05 FRANCE 11/38

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

  13. Salle Jaune Laser based on CPA technique 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 After Compression : 1 J, 30 fs, 0.8 mm, 10 Hz, 10 -7 2 m Journées accélérateurs, SFP, Roscoff 05 FRANCE 13/38

  14. . ) -3 1 9 1 1 0 16 10 ) 1 8 8 1 0 -3 1 8 cm 6 1 0 1 8 4 1 0 18 Densité de neutre (cm 5 5 1 8 Phase (radians) 2 1 0 0 Density (10 - 4 - 3 - 2 - 1 0 1 2 3 4 1 0 The target gas jet Developed at the gas jet’s lab z z 2 mill. 2 mill. 2 mill. rayon 2 mill. rayon Rayon (mm) V. Malka et al., RSI (2000) Journées accélérateurs, SFP, Roscoff 05 FRANCE 14/38

  15. Gas Jet Nozzle Design and improvement For laser plasma studies cm-3 D crit D exit L opt Mach N ext cm-3 D crit D exit L opt Mach N ext mm mm mm exit mm mm mm exit 19 19 1 2 6 3.5 18 x 10 0.5 1 4 3.3 16 x 10 19 19 1 3 7 4.75 7.5 x 10 0.5 2 5 5.5 4.5 x 10 19 19 1 5 10 7 2.7 x 10 0.5 3 5 6.2 2.1 x 10 19 19 1 10 15 10 0.75 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

  16. 10 10 100 Ne=1.5x1019cm-3 Ne=1.5x1020cm-3 9 10 # electrons/MeV/sr T =8.1 MeV 8 eff 10 T =2.6MeV eff 7 10 detection threshold 10 W (MeV) 6 19 20 10 10 10 0 10 20 30 40 50 60 70 d n E = 4 g m c 2 2 n max p e F/6 Tunable electron beam : temperature Electrons are accelerated by epw (MeV) max INCREASE THE ACCELERATION LENGTH E -3 n (cm ) e V. Malka et al., PoP (2001) Journées accélérateurs, SFP, Roscoff 05 FRANCE 16/38

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

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

  19. Electron bunch laser Electron density perturbation ne/n0-1 laser Electric field Electron bunches 0 Electric field fs Ps SMLWF : Multiple e- bunches / FLWF Single e- bunch V. Malka, Europhysics news, April 2004 (Ps/fs) Journées accélérateurs, SFP, Roscoff 05 FRANCE 19/38

  20. One stage LPA Quasi-Monoenergetic Electron BeamsIn homogenous plasma : virtual or real? VLPL Time evolutionof electron spectrum N / MeV e 9 1 10 t=750 t=650 t=850 monoenergeticelectron beam t=550 8 t=450 5 10 t=350 0 200 400 E, MeV A.Pukhov & J.Meyer-ter-Vehn, Appl. Phys. B, 74, p.355 (2002) Journées accélérateurs, SFP, Roscoff 05 FRANCE 20/38

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

  22. Spatial quality improvements 5.0 x1019cm-3 3.0 x 1019cm-3 2.0 x 1019cm-3 6.0 x1018cm-3 1.0 x1019cm-3 7.5 x1018cm-3 Divergence = 6 mrad Journées accélérateurs, SFP, Roscoff 05 FRANCE 22/38

  23. From Mono to maxwellian spectra : the bubble regime : optimum when ctL lp V. Malka, et al., PoP 2005 Journées accélérateurs, SFP, Roscoff 05 FRANCE 23/38

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

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

  26. GeV acceleration in two-stages Laser Gas-Jet Laser Plasma channel GeV • 1 J • 10 TW • 30 fs • 50-150 TW • ~50 fs Nozzle • 170±20 MeV • 30 fs • 10 mrad Density profile rc Δn • Pulse guiding condition : Δn>1/πre rc2 n0 • Weak nonlinear effects more control : a0 ~ 1-2 • High quality beams : Lb <λp n0<1018 cm-3 Journées accélérateurs, SFP, Roscoff 05 FRANCE 26/38

  27. n0=8 1016 cm-3, 11 J - 140 TW rc=40 μm, Δn=2 n0 4 8 cm L channel=4 cm 12 cm 3 dN/dE(a.u.) 2 1 0 0 800 400 1200 Energy (MeV) GeV in low plasma density in plasma channel GeV in low plasma density in plasma channel Electric field Electron bunch Electric field Electron bunch V. Malka et al., to be published in Royal Society and Phil. Trans. Journées accélérateurs, SFP, Roscoff 05 FRANCE 27/38

  28. Very important for: • Biology • Ionising radiations effects B. Brozek-Pluska et al., Radiation and Chemistry, 72, 149-159 (2005) **Ar. On the ultra short duration benefit fs radiolysis : H2O (e-s, OH., H2O2, H3O+, H2, H.) e- Journées accélérateurs, SFP, Roscoff 05 FRANCE 28/38

  29. In collaboration with L. Le-Dain, S. Darbon from CEA Mourainvilier and DAM Material science: g-ray radiography High resolution radiography of dense object with a low divergence, point-like electron source Glinec et al., PRL 94 p025003 (2005) Journées accélérateurs, SFP, Roscoff 05 FRANCE 29/38

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

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

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

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

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

  35. ゝ ゝ ゝ ゝ ゝ ゝ ゝ ゝ ゝ The laser plasma accelerators status • Laser plasma acceleration has demonstrated • Energy gains of 1 MeV to 200 MeV • E-fields of 1 GV/m to 1000 GV/m • Good e-beam quality : Emittance < 3pmm.mrad • charge at high energy • Quasi monoenergetic • Laser plasma accelerators advantages • 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 Journées accélérateurs, SFP, Roscoff 05 FRANCE 35/38

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

  37. = m m w 20 - = ´ 18 3 n 1 . 5 10 cm 0 p t = 30 fs = P 200 TW l = m 0 . 8 m = a 4 0 2.5 2 1.5 1 » L 1 . 0 cm T 0.5 » L 1 . 3 cm dp 0 800 1200 1600 2000 D » E 1 . 5 GeV Next Step: GeV electron beams (1 stage) Total charge = 1.1 nC f(E) (a.u.) P » 10 P c After 5 Zr / 7.5 mm Energy (MeV) * Gordienko et al, PoP 2005, UCLA group Journées accélérateurs, SFP, Roscoff 05 FRANCE 37/38

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

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