Progress with Laser Plasma Acceleration and Prospects of LPA HEP Colliders Wim Leemans LOASIS Program and BELLA Team APS-DPF Meeting August 12, Lawrence Berkeley National Laboratory UC Berkeley

2 SLAC 50 GeV 7 TeV LHC Accelerators: drivers for science DNADNA 2 GeV X-rays

Laser plasma acceleration enables development of “compact” accelerators 3 m-scale 100 micron-scale 10 – 40 MV/m 10 – 100 GV/m Plasmas sustain extreme fields => compact accelerators Can this technology be developed for energy frontier machines, light sources, medical or homeland security applications? ΔW=E z x L

Wish list for an e + - e - TeV collider... Energy = O(1 TeV, c.m.) Length = O(soccer field) E z = O(10 GV/m) Luminosity > cm -2 s -1 Cost = Affordable Beam power, beam quality Wall plug efficiency, technology choice

Key technical challenges for Laser Plasma Accelerators Multi-GeV beams Lasers: high average power Modeling High quality beams laser Staging, optimized structures TW Diagnostics/Radiation sources PW-class BELLA

7 Channel guided laser plasma accelerators have produced up to GeV beams from cm-scale structures C. G. R. Geddes,et al, Nature,431, p538 (2004) S. Mangles et al., Nature 431, p535 (2004) J. Faure et al., Nature 431, p541 (2004) 2004 result: 10 TW laser, mm-scale plasma 2006 result: 40 TW laser, cm-scale plasma W.P. Leemans et. al, Nature Physics 2, p696 (2006) K. Nakamura et al., Phys. Plasmas 14, (2007) 1.1 GeV <2.9% <1 mrad pC ~100 MeV

A GeV module…

Electrons surfing on a wave: controlled injection Injected Electrons Injected Out of Phase Self Injection Trapping requires: -Tsunami - Boost electrons or slow down wave

Longitudinal density tailoring allows trapping control S.V. Bulanov et al., PRL 78, (1997); Geddes et al., PRL V 100, (2008); A.J. Gonsalves et al., submitted (2010)

Practical implementation of combined injector and acceleration stage 11 Laser Injector Acceleration section GeV 3 cm Supersonic gas jet embedded into capillary

12 Tunable electron beams produced with jet+capillary module using laser focus control A.J. Gonsalves et al., accepted Nature Physics Jet density 7 × cm −3 Capillary density 1.8 × cm −3, a 0 ~1.5 Energy variation for fixed focus <1.9 % rms Divergence change < 0.57 mrad rms Energy variation < 2 % rms Charge variation < 6 % rms Divergence change < 0.57 mrad rms

Electron beam can be steered using plasma channel alignment  cap (mrad)  cap laser axis capillary axis High Center Low

14 Techniques for improving beam quality, reproducibility, control being improved ‣ Tunable energy, low Δ E/E laser e - beam Coherent Optical Transition Radiation ‣ Beam detection and transport ‣ Emittance control via laser mode Laser E trans E long

15 First XUV light observed from LPA beam through THUNDER undulator e-beam from LPA imaged with quadrupole magnets ~ 7.5 meter Undulator Magnetic spectrometer XUV spectrometer Beam diagnostics XUV light Electron beam spectra ~40 nm

Key technical challenges for Laser Plasma Accelerators Multi-GeV beams Lasers: high average power Modeling High quality beams laser Staging, optimized structures TW Diagnostics/Radiation sources PW-class

17 Staging: solving the issue of depletion of laser energy Injector+capillary Structure-to-structure laser Staging  Experiments underway at LBNL  Key technology for collider Plasma mirror Regular mirror Mirror Size (meter) Damage threshold sets mirror size Power (TW) Renewable mirrors or tape LPA 1LPA 2

Key technical challenges for Laser Plasma Accelerators Multi-GeV beams Lasers: high average power Modeling High quality beams laser Staging, optimized structures TW Diagnostics/Radiation sources PW-class

C.B. Schroeder et al., PRSTAB 2010

20 BELLA Facility: state-of-the-art PW-laser for laser accelerator science BELLA Laser Control Room Gowning Room CompressorPlasma source 10˚ Off-axis parabola High power diagnostic

21 Amp2 (22 J) accepted – June 2011 BELLA Laser System Status – 2011 Summer 12 Gaia-s operational in laser room – July 2011 Amp3 (61 J) components installed – July 2011 Compressor chamber manufactured – July 2011

22 Petawatt, 1 Hz BELLA laser enables R&D on 10 GeV collider module < 100 cm 1000 TW 40 fs e - beam ~10 GeV Laser Accelerator science studies - 10 GeV Module for collider, (10 GeV, beam optimization, efficiency etc…) - Positron production; plasma wakefield acceleration, etc... Applications:  Hyperspectral radiation: coherent THz; X-ray FEL driver - Detector testing; Non-linear QED 2013 Experiments Lorentz boosted frame simulation Full 1 m BELLA stage -- major advance Courtesy of J.-L. Vay

Key technical challenges for Laser Plasma Accelerators Multi-GeV beams Lasers: high average power Modeling High quality beams laser Staging, optimized structures TW Diagnostics/Radiation sources PW-class

Laser plasma accelerator (today) Collider (>20 yrs) Lightsource (10 yrs) Security Apps (5-10 yrs) Medical (10 yrs) Laser development

25 1 TeV case: 420 kW/laser, 13 kHz (32 J/pulse) with 30% wall plug efficiency and we need 100 of them

26 Laser technology: key component for sustained progress How to reach laser average power levels needed for science apps? Develop roadmap for science and technology to develop next generation lasers: –Important for accelerators (see Accelerators for America’s Future document) –Unique differences between lasers for defense and for science –Will require major research investment at National Labs, Universities and Industry with potential for international collaborations –ICFA-ICUIL Joint Taskforce for roadmap development

27 Novel lasers and materials are being developed ‣ Amplifiers - Rods, slabs, discs and fibers ‣ Materials for amplifiers, mirrors and compressor gratings - Ceramics and diamond - Nano-fabricated structures ‣ Diodes and small quantum defect materials O(10 kW) fibers (CW power) reality now!

28 Major investments - Example: European Extreme Light Infrastructure - Four pillars (three funded at 790Meuro): 1. attosecond and XUV science: Hungary 2. High-brightness x-ray and particle sources: Czech Republic 3. Photo-nuclear science, transmutation,...: Romania 4. Ultra-high intensity science (non-lin QED): Russia ???

30 Conclusion ‣ Laser plasma accelerator science is vibrant - GeV beam demonstrated with %-level energy spread - BELLA facility aims at 10 GeV in 1 meter - FEL proof-of-principle experiments towards Light Source Facility - Gamma-ray sources, medical and other applications ‣ Collider is still far off but basic concepts are being developed: - Operation in quasi-linear regime for e- and e+ acceleration - Transverse control of plasma profile for guiding laser beam - Injection control and efficiency optimization: - Longitudinal control of plasma profile - Laser mode control allows emittance control - Low emittance observed -- FEL experiment will be litmus test ‣ Laser technology must undergo revolution towards high average power 30

Team, collaborators and funding Primary collaborators Postdocs K. Nakamura (E) M. Chen (S) C. Benedetti (S+T) T. Sokollik (E) Students M. Bakeman (PhD) -- graduated 2011 C. Lin (PhD) -- graduated 2011 R. Mittal (PhD) G. Plateau (PhD) -- graduating 2011 S. Shiraishi (PhD) D. Mittelberger (PhD) C. Koschitzki (PhD) B. Shaw (PhD) L. Yu (PhD) Staff S. Bulanov (T, UCB) E. Esarey (T) C. Geddes (S+E) A. Gonsalves (E) W. Leemans (E) N. Matlis (E) C. Schroeder (T) C. Toth (E) J. van Tilborg (E) Eng/Techs R. Duarte Z. Eisentraut A. Magana S. Fournier D. Munson K. Sihler D. Syversrud N. Ybarrolaza LBNL: M. Battaglia, W. Byrne, J. Byrd, W. Fawley, K. Robinson, D. Rodgers, R. Donahue, Al Smith, R. Ryne. TechX-Corp: J. Cary, D. Bruhwiler, et al. SciDAC team Oxford Univ.: S. Hooker et al. DESY/Hamburg: F. Gruener et al. GSI: T. Stoehlker, D. Thorn Trieste: F. Parmigiani BELLA Team members S. Zimmermann J. Coyne D. Lockhart G. Sanen S. Walker-Lam K. Barat

Collider power and efficiency requirements: well beyond current state-of-the-art  Beam power: P b = fNE cm N ~ 4x10 9 f ~ 15 kH z E cm ~ 1 TeV P b ~ 4.8 MW  Collider based on 10-GeV stages:  ~32 J/laser at 15 kHz = ~480 kW average power laser/stage (100 stages) Well beyond state-of-the-art for high peak power laser technology  Laser technology development required  ~20% laser to beam efficiency  ~30% wall-plug to laser efficiency  Laser to plasma wave efficiency: ~50%  Plasma wave to beam efficiency: ~40% 6% efficiency => AC wall-plug power ~ 80 MW

33