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Laser Plasma Accelerators: Principle & applications

LOA. Laser Plasma Accelerators: Principle & applications. Victor Malka Laboratoire d’Optique Appliqu é e ENSTA-Ecole Polytechnique , CNRS 91761 Palaiseau, FRANCE. Partially supported by CARE/PHIN FP6 project. John Adams Insitute, Oxford UK, January 10, 2008. LOA. Acknowledgement. SPL.

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Laser Plasma Accelerators: Principle & applications

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  1. LOA Laser Plasma Accelerators: Principle & applications Victor Malka Laboratoire d’Optique Appliquée ENSTA-Ecole Polytechnique, CNRS 91761 Palaiseau, FRANCE Partially supported by CARE/PHIN FP6 project John Adams Insitute, Oxford UK, January 10, 2008

  2. LOA Acknowledgement SPL ELF Particle group J. Faure Y. Glinec A. Lifschitz C. Rechatin Laser group F. Burgy B. Mercier J.Ph. Rousseau Collaborators • Pukhov, University of Dusseldorf, Germany E. Lefebvre,CEA/DAM Ile-de-France, France John Adams Insitute, Oxford UK, January 10, 2008

  3. LOA Summary • Part 1 : Laser plasma accelerator : motivation • Part 2 : Laser Plasma accelerator as injector : Production of monoenergetic electron beam • Part 3 : New scheme of injection : toward a stable, tuneable and quasi monoenergetic electron beam. Part 4 : Applications Part 5 :Conclusion and perspectives John Adams Insitute, Oxford UK, January 10, 2008

  4. LOA 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 John Adams Insitute, Oxford UK, January 10, 2008

  5. Plasma is an Ionized Medium High Electric Fields w E ~ ~ n z p e LOA Why is a Plasma useful ? • Superconducting RF-Cavities : Ez = 55 MV/m John Adams Insitute, Oxford UK, January 10, 2008

  6. 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 z e F≈-grad I Electron density perturbation Laser pulse Phase velocity vfepw=vglaser=> close to c Analogy with a boat Tajima and Dawson, PRL (1979) LOA How to excite Relativistic Plasma waves? The laser wake field tlaser≈ Tp / 2 =>Short laser pulse Tajima&Dawson, PRL79 John Adams Insitute, Oxford UK, January 10, 2008

  7. d g => E (MeV)­( n/n)(n /n ) 2 2 d n/n) mc E =2( f max c e max l l g 3/2 =>L =( /2)(n /n ) 2 = L f deph. 0 c e p Deph. LOA Analogy electron/surfer t t t 3 1 2 électron g g > > > > 1 f e Analogy: John Adams Insitute, Oxford UK, January 10, 2008

  8. LOA John Adams Insitute, Oxford UK, January 10, 2008

  9. 100 mm Plasma cavity Classical accelerator limitations Courtesy of W. Mori & L. da Silva 1 m RF cavity LOA John Adams Insitute, Oxford UK, January 10, 2008

  10. LOA Summary • Part 1 : Laser plasma accelerator : motivation • Part 2: Laser Plasma accelerator as injector : Production of electron beam • Part 3 : New scheme of injection : toward a stable, tuneable and quasi monoenergetic electron beam. Part 4 : Applications Part 5 :Conclusion and perspectives John Adams Insitute, Oxford UK, January 10, 2008

  11. 50 cm Laser beam electron beam LOA Interaction chamber (inside) John Adams Insitute, Oxford UK, January 10, 2008

  12. LOA Laser plasma injector Scheme of principle Experimental set up John Adams Insitute, Oxford UK, January 10, 2008

  13. LOA 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 John Adams Insitute, Oxford UK, January 10, 2008

  14. LOA Recent results on e-beam : From Mono to maxwellian spectra Electron density scan V. Malka, et al., PoP 2005 John Adams Insitute, Oxford UK, January 10, 2008

  15. Divergence = 6 mrad LOA Energy distribution improvements: The Bubble regime Charge in the peak : 200-300 pC Experiment PIC At LOA J. Faure et al. Nature (2004) John Adams Insitute, Oxford UK, January 10, 2008

  16. LOA Other results RAL & LBNL also to be published tomorrow in Nature 04 50 pC 300 pC RAL & LBNL John Adams Insitute, Oxford UK, January 10, 2008

  17. LOA S. Mangles et al., C. Geddes et al., J. Faure et al., in Nature 30 septembre 2004 John Adams Insitute, Oxford UK, January 10, 2008

  18. Quasi-monoenergetic beamsreported in the litterature Intensity tL/Tp Remark Energy dE/E Charge Ne Article Name Lab /cm ] [x10 W/cm ] 18 2 [pC] [x1018 3 [MeV] [%] Mangles Nature (2004) RAL 73 6 22 20 2,5 1,6 Geddes Nature (2004) L'OASIS 86 2 320 19 11 2,2 Channel Faure Nature (2004) LOA 170 25 500 6 3 0,7 Hidding PRL (2006) JETI 47 9 0,32 40 50 4,6 Hsieh PRL (2006) IAMS 55 336 40 2,6 Hosokai PRE (2006) U. Tokyo 11,5 10 10 80 22 3,0 Preplasma Miura APL (2005) AIST 7 20 432E-6 130 5 5,1 Hafz PRE (2006) KERI 4,3 93 200 28 1 33,4 Mori ArXiv (2006) JAERI 20 24 0,8 50 0,9 4,5 Mangles PRL (2006) Lund LC 150 20 20 5 1,4 Several groups have obtained quasi monoenergetic e beam but at higher density (tL>tp) LOA John Adams Insitute, Oxford UK, January 10, 2008

  19. GeV electron beams from a « centimetre-scale » accelerator 310-μm-diameter channel capillary P = 40 TW density 4.3×1018 cm−3. Leemans et al., Nature Physics, september 2006 LOA John Adams Insitute, Oxford UK, January 10, 2008

  20. LOA Summary • Part 1 : Laser plasma accelerator : motivation • Part 2: Laser Plasma accelerator as injector : Production of monoenergetic electron beam • Part 3 : New scheme of injection : toward a stable, tuneable and quasi monoenergetic electron beam. Part 4 : Applications Part 5 :Conclusion and perspectives John Adams Insitute, Oxford UK, January 10, 2008

  21. electrons Principle: Pump beam Injection beam Plasma wave LOA Controlling the injection pump injection Counter-propagating geometry: Ponderomotive force of beatwave: Fp ~ 2a0a1/λ0 (a0 et a1 can be “weak”)y Boost electrons locally and injects them:y INJECTION IS LOCAL IN FIRST BUCKETy E. Esarey et al, PRL 79, 2682 (1997), G. Fubiani et al. (PRE 2004) John Adams Insitute, Oxford UK, January 10, 2008

  22. 250 mJ, 30 fs ffwhm=30 µm I ~ 4×1017 W/cm2 a1=0.4 700 mJ, 30 fs, ffwhm=16 µm I ~ 3×1018 W/cm2 a0=1.2 LOA Experimental set-up to shadowgraphy diagnostic electron spectrometer Probe beam LANEX Gas jet B Field Injection beam Pump beam John Adams Insitute, Oxford UK, January 10, 2008

  23. LOA John Adams Insitute, Oxford UK, January 10, 2008

  24. pump Single beam ne=1019 cm-3 Self-injection Threshold ne=7.5×1018 cm-3 injection pump ne=7.5×1018 cm-3 2 beams LOA From self-injection to external injection ne=1.25×1019 cm-3 John Adams Insitute, Oxford UK, January 10, 2008

  25. LOA Optical injection by colliding pulses leads to stable monoenergetic beams STATISTICS value and standard deviation Bunch charge= 19 +/- 6 pC Peak energy= 117 +/- 7 MeV DE= 13 +/- 2.5 MeV DE/E= 11 % +/- 2 % Divergence= 5.7 +/- 2 mrad Pointing stability= 2 mrad *Charge measurements with absolute calibration of Lanex film (ICT gave a factor of 8 higher charge) John Adams Insitute, Oxford UK, January 10, 2008

  26. LOA Monoenergetic bunch comes from colliding pulses: polarization test Parallel polarization Crossed polarization John Adams Insitute, Oxford UK, January 10, 2008

  27. LOA Controlling the bunch energy by controlling the acceleration length By changing delay between pulses: • Change collision point • Change effective acceleration length • Tune bunch energy Injection beam Pump beam 2 mm Gas jet John Adams Insitute, Oxford UK, January 10, 2008

  28. injection pump Zinj=225 μm Zinj=125 μm late injection Zinj=25 μm injection pump Zinj=-75 μm Zinj=-175 μm middle injection Zinj=-275 μm injection pump Zinj=-375 μm early injection LOA Tunable monoenergetic bunches J. Faure et al., Nature 2006 John Adams Insitute, Oxford UK, January 10, 2008

  29. LOA Tunable monoenergetic electrons bunches: 190 MeV gain in 700 µm: E=270 GV/m Compare with Emax=mcwp/e=250 GV/m at ne=7.5×1018 cm-3 John Adams Insitute, Oxford UK, January 10, 2008

  30. LOA Summary Part 1 : Laser plasma accelerator : motivation Part 2 : Laser Plasma accelerator as injector : Production of monoenergetic electron beam Part 3 : New scheme of injection : toward a stable, tuneable and quasi monoenergetic electron beam. Part 4 : Applications Part 5 :Conclusion and perspectives John Adams Insitute, Oxford UK, January 10, 2008

  31. LOA 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 John Adams Insitute, Oxford UK, January 10, 2008

  32. LOA GeV in low plasma density in plasma channel n0=8 1016 cm-3, 11 J - 140 TW rc=40 μm, Δn=2 n0 Electric field 4 8 cm L channel=4 cm 12 cm 3 Electron bunch dN/dE(a.u.) 2 Electric field 1 0 0 800 400 1200 Energy (MeV) Electron bunch V. Malka et al., Plasma Phys. Control. Fusion 47 (2005) B481–B490 John Adams Insitute, Oxford UK, January 10, 2008

  33. LOA Injecting the LOA e-beam @ tbunch = 30 fs, 170 MeV John Adams Insitute, Oxford UK, January 10, 2008

  34. LOA 3 GeV, 1% energy spread e-beam • E=9 J • P= 0.15 PW • a0=1.5 • Parabolic channel: • r0=47 m, • n(r)=n0 (1+0.585 r/r0) • n0 = 1.1×1017 cm-3 3.5 GeV, with a relative energy spread FWHM of 1% and an unnormalized emittance of 0.006 mm. V. Malka et al., PRSTA 9, 091301 2006 John Adams Insitute, Oxford UK, January 10, 2008

  35. In collaboration with CEA / DAM LOA Material science: g-ray radiography High resolution radiography of dense object with a low divergence, point-like electron source Glinec et al., PRL 94 025003 (2005) John Adams Insitute, Oxford UK, January 10, 2008

  36. g-radiography results 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 Glinec et al., PRL 94 025003 (2005) LOA John Adams Insitute, Oxford UK, January 10, 2008

  37. Particle beam in medicine : Radiotherapy 99% Radiotherapy with X ray LOA John Adams Insitute, Oxford UK, January 10, 2008

  38. Photon beam Radiation Therapy : context Photon beams are commonly used for radiation therapy Photon dose Dose tumor tumor Depth in tissue LOA John Adams Insitute, Oxford UK, January 10, 2008

  39. VHE ELECTRONS Medical application : Radiotherapy LOA John Adams Insitute, Oxford UK, January 10, 2008

  40. VHE VHE Radiation Therapy • Reduced dose in save cells • Deep traitement • Good lateral contrast Dose VHE dose tumor tumor Depth in tissue LOA John Adams Insitute, Oxford UK, January 10, 2008

  41. LOA Clinically approved prostate treatment with seven fields irradiation Transversal view Sagittal view John Adams Insitute, Oxford UK, January 10, 2008

  42. LOA Improved treatment with electrons A typical transversal dose distribution with 7 beams. Electrons Photons Difference A comparison of dose deposition with 6 MeV X ray an improvement of the quality of a clinically approved prostate treatment plan. While the target coverage is the same or even slightly better for 250 MeV electrons compared to photons the dose sparing of sensitive structures is improved (up to 19%). T. Fuchs, DKFZ in preparation John Adams Insitute, Oxford UK, January 10, 2008

  43. Very important for: • Biology • Ionising radiations effects B. Brozek-Pluska et al., Radiation and Chemistry, 72, 149-159 (2005) **Ar. Fudamental aspect :fs radiolysis H2O (e-s, OH., H2O2, H3O+, H2, H.) e- LOA John Adams Insitute, Oxford UK, January 10, 2008

  44. 10cm q ~ mrad Compact XFEL: towards a bright X ray source Reduction of accelerator Reduction of the undulator Applications: study of complex structures (X-ray diffraction, EXAFS) But ps time scale LOA John Adams Insitute, Oxford UK, January 10, 2008

  45. LOA Parameter designs Laser Plasma Accelerators ELI : > 100 GeV a0=4 P(PW) τ (fs) ne(cm-3) W0(μm) L(m) E(J) Q(nC) E(Gev) 0.12 30 2e18 15 0.009 3.6 1.3 1.12 1.2 100 2e17 47 0.28 120 4 11.2 12 300 2e16 150 9 3.6k 13 112 120 1000 2e15 470 280 120k 40 1120 Golp and UCLA Group John Adams Insitute, Oxford UK, January 10, 2008

  46. LOA Conclusions / perspectives SUMMARY • Optical injection by colliding pulse: it works ! • Monoenergetic beams trapped in first bucket • Enhances dramatically stability • Energy is tunable: 15-300 MeV • Charge up to 80 pC in monoenergetic bunch • dE/E down to 5 % (spectrometer resolution), dE ~ 10-20 MeV • Duration shorter than 10 fs. PERSPECTIVES Q • Combine with waveguide: tunable up to few GeV’s with dE/E ~ 1 % • Design future accelerators • Model the problem for further optimization: higher charge • Stable source: extremely important • accelerator development (laser based accelerator design) • light source development for XFEL • applications (chemistry, radiotherapy, material science) John Adams Insitute, Oxford UK, January 10, 2008

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