Summary Working Group 4: Plasma Wakefield Acceleration

Transcription

1 Summary Working Group 4: Plasma Wakefield Acceleration James Rosenzweig, Andrei Seryi Working group leaders On behalf of the working group AAC 2010 Annapolis, MD June 19, 2010

2 Future Experimental Facilities

3 Presented by Weiming An, UCLA

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7 Drive Beam Shaping and Witness Bunch Generation for the Plasma Wakefield Accelerator Advanced Accelerator Research Department Stanford Linear Accelerator Center R. Joel England* J. Frederico*, M. J. Hogan*, P. Muggli, G. Travish, J. B. Rosenzweig, C. Joshi *SLAC, USC, UCLA Advanced Accelerator Concepts Workshop June 13-19, 2010

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9 FACET Chicane Optics R cartoon: not to scale isochronous configuration: R56 = -0.1mm; T566 = -0.5mm; beta functions well-constrained 9 Advanced Accelerator Concepts Workshop June 13-19, 2010

10 PWFA facility at Budker INP, Novosibirsk (A. Petrenko) e+ Damping Ring 500 MeV Linac e- Electron beam obtained in the damping ring: PWFA facility E = MeV N(e ) = σ S = 8 mm (I peak = 50 A)

11 Main goal: demonstration of beam quality in a high gradient plasma wake-field accelerator Agenda includes long-pulse hosing, multi-bunch studies

12 Ultra-high Gradient Approaches

13 Breaking the attosecond, Å, and TV/m barriers with low-charge, ultra-fast beams J.B. Rosenzweig, et al. Proposal for ultra-short, low-q (pc) beams in FEL Unprecedented brightness Single spike operation Breaching attosecond, short wavelength frontier Scaling the PWFA to short wavelength TV/m PWFA experiment at the LCLS z Beam brightness x 100, with <fs pulses -> fs single spike (SPARX case)

14 Progress, Applications of Low-Q fs Electron Beams Marry with new undulators: Ccompact FEL,v. hard X-rays Gain evolution at 13.6 GeV, 0.15 Å LCLS experiments: 20 pc, 2 fs pulses, 0.14,0.4 mm-mrad achieved. Focus to <200 nm: allows TV/m PWFA scenario. BSI ionization, ion motion, OCTR! >TV/m long. wakes H ionization complete inside beam Ion density distortions

15 Hybrid Laser-Plasma Wakefield Acceleration Bernhard Hidding, T. Königstein, J. Osterholz, O. Willi, G. Pretzle,S. Karsch, J.B. Rosenzweig witness driver 1. LWFA/SMLWFA: double-bunches on fs-scale 12 µm 2. Driver/witness PWFA afterburner doubles witness electron energy monoenergetically Witness (and driver) is focussed to charge densities which have transversal self-fields beyond ionization thresholds May also be strategy for increased laser-to-beam transfer, and for fs-res. Bunch distance measurements (ATF, FACET PWFA?)

16 TV/m-scale fields, monoenergetic energy doubling LWFA and PWFA are (re-)coalescing! Bernhard Hidding et al., 104, 2010

17 Positively Charged Beams in PWFA

18 Update of proton driven plasma wakefield acceleration G. Xia, A. Caldwell, Max Planck Institute fur Physik, Munich, Germany Presented by P. Muggli, USC High energy stored in current proton machines like Tevatron, HERA, SPS and LHC LHC (1 TeV, 1.15e11 p/bunch) ~ 20 kj/bunch ILC (1TeV GeV, 2e10 e-/bunch) ~ 3 kj/bunch However, the proton bunches are too long to be used as driver directly. Need to compress them. If we can couple the energy of drive beam to the plasma and the witness beam efficiently, a new plasma wakefield acceleration frontier can be opened. Scientific goals: Near-term plan is to use the extracted proton beam from the PS or SPS to demonstrate the energy gain of 1 GeV within 5 m of plasma These experiments should also lead to a scheme to achieve 100 GeV energy gain per 100 m plasma

19 E acc E foc n e n b With short p + bunch and injected e - bunch: e - p + 600GeV e - bunch First experiments: Two stream instability modulates the long p + at the plasma wavelength The modulation resonantly drives wakefields in the MV/m with CERN SPS beam <1% E/E In ~500m plasma Letter of intent for experiment at CERN will be prepared soon based on the recent simulation results.

20 Concept for (multi)-tev upgrade of ILC based on protondriven plasma acceleration Presented by A. Seryi Proton bunches are accelerated together with e- (e+) bunches in 1.3 GHz SC linac of ILC, separated by a fraction of the RF wavelength. The protonphase slippage of is controlled by special sailboat chicanes inserted between linac sections. Locations and settings of the chicanes can also be optimized to compress the proton bunch, as needed for PWFA. There are many challenges in this scheme that need to be further analyzed

21 Dual path chicane similar to this one designed for FACET (which provides 5cm path length difference for 23 GeV e- and e+ bunches) will be used to control phase slippage Acceleration of a proton bunch from 8 to 20 GeV in ILC linac, modified to include phase-slippage-control double chicane sections. Different sections are indicated by different color Ballistic compression of a proton performed simultaneously with its acceleration

22 Positron driven plasma wakefields S. Pinkerton*, Y. Shi*, C. Huang, P. Muggli* A pancake shaped bunch is able to drive a similar wake to the electron case. Not in the blowout regime. Preliminary simulations suggest a better blow out comes at the cost of lower gradient. Support: NSF and US DoE *University of Southern California; Los Alamos National Lab

23 Positron driven plasma wakefields S. Pinkerton*, Y. Shi*, C. Huang, P. Muggli* Facilities SLAC s FACET can produce the positron bunch and plasma source needed to run these experiments with essentially the same equipment already in place for electron PWFA. With the installation of the sailboat chicane, an electron witness bunch will be available to sample the wake. Future Work Develop theory to find ideal bunch geometry, plasma density, and other parameters. Explore the parameter space for better blow out with a significant gradient. Run long simulations (also via OSIRIS) to investigate head erosion, phase slippage, wake evolution, etc. Design and run experiments at FACET.

24 Resonant excitation of PWFA

25 Resonant Excitation of Plasma Wakefields P. Muggli, B. Allen. University of Southern California, Los Angeles, CA M. Babzien, K. Kusche, J. Park, M. Fedurin, V. Yakimenko, Brookhaven National Laboratory, Upton, Long Island, NY A train of equidistant e - bunches drives large accelerating wakefields in high density plasmas (train period z= pe, linear PWFA regime) A witness bunch gains large energy with large transformer ratio and high efficienc (with tailored charge) WARNING: NOT simulations! Experimental Data! Kimura, AAC 06 Proceedings Generate bunch train with recently demonstrated masking technique Mask can be designed to tailor train time structure for specif application For resonant PWFA: equidistant drive train ( z period) followed by witness bunch with witness at z =1.5 z

26 Send train into a capillary discharge plasma Vary the discharge-train delay to vary the plasma density, i.e., the accelerator frequency Preliminary results: Resonance clearly observed with large energy loss and energy gain All the expected physics is observed Plan: Drive wakefields with various # of drive bunches Block witness bunch to confirm origin of accelerated particles Reverse train chirp to place witness bunch at high incoming energy Tailor bunch charge with 2D mask to demonstrate large transformer ratio (>2) Focus beam tightly to explore quasi-non-linear regime Use train for DLA experiments, CSR suppression, etc. Experiments to explore the PWFA physics and test-bed for very involved high energy experiments (SLAC-FACET, etc.)

27 Optical Frequency Domain Visualization of Electron Beam Driven Plasma Wakefields (under development at BNL ATF). Rafal Zgadzaj, Michael C. Downer, (UT Austin) Patrick Muggli (USC) Vitaly Yakimenko, Karl Kusche, Marcus Babzien, Mikhail Fedurin (BNL/ATF) 2 or multi-bunch e beam STRETCHER witness drive EO CRYSTAL EO Spectrometer Electro optic signal Probe Reference Correlated measurements of bunch and laser delay, bunch profiles, and plasma wave structure. ~ 1mm witness drive FDH Spectrometer Reference Probe Frequency Domain Holography signal Laser Laser beam 1. Yb-fiber laser with τ ~ 200fs L ~ 1-2 cm H2 Discharge Capillary n e ~ to cm -3 p ~ 1.1ps to 0.35ps Electro optic (EO) sampling of e-bnches A. L. Cavalieri, Clocking Femtosecond X Rays, PRL 94, (2005). Tilborg et al., WG5, AAC 2010 Matlis et al., Plenary, AAC 2010 n e /n e ~ 10-2 Frequency Domain Iterferometry (FDI) Tokunaga et al., Optics Lett. 17, 1131 (92) Siders et al., PRL 76, 3570 (96) Marqués et al., PRL 78, 3463(97) Kotaki et al., Phys. Plasmas 9, 1392 (02) Frequency Domain Holography (FDH) Tokunaga et al., Optics Lett. 17, 1131 (92) Siders et al., PRL 76, 3570 (96) Marqués et al., PRL 78, 3463(97) Kotaki et al., Phys. Plasmas 9, 1392 (02)

28 Other approaches may be necessary and are being developed: Optical bullets (demonstrated in LWFA), Frequency Domain Streak Camera (FDSC)(demonstrated in glass), Frequency Domain Tomography (under development) Averaged projection Zhenyan Li et al., WG1, AAC 2010 Projection vs. time tail tail Z=0 front edge Probe + Reference Raw Spectrum Reconstructed amplitude of Probe Electron Spectrum Simulation: Austin Yi, Gennady Shvets, UT Austin See Xaomng Wang et al., WG1, AAC 2010 Optical Bullets Signature of bubble formation Dong, et al., Formation of Optical Bullets in Laser-Driven Plasma Bubble Accelerators, Nature Physics, 2, (2006) Also: WG1, AAC 2010 Frequency Domain Tomography (FDT) Full shape vs. time

29 The Quasi-Nonlinear Regime of the Plasma Wakefield Accelerator James Rosenzweig, Gerard Andonian, Oliver Williams, Ken Xuan (UCLA), Massimo Ferrario (INFN-LNF), Patric Muggli (USC), Vitaly Yakimenko (BNL) Multiple pulse beam-loaded operation in linear collider Critical for efficiency Accelerating beam Driving beam Need blowout for accelerating/focusing qualities But negative aspects of nonlinearities serious: Amplitude dependent period Wavebreaking, snowplow (inefficiency, heating) New regime: quasi-nonlinear Underdense n b n 0 Very narrow (low emittance, highly focusable) Low total charge 3 Q N bk p n 0 1 k p r 1

30 Quasi-linear PWFA Wakes resonant at linear plasma frequency Little wave-breaking, stable wakes 4-pulse train, Q~=0.11, n b /n 0 =20, SPARX case Experiments feasible at BNL, SPARX

31 Instabilities

32 Plasma Astrophysics in the Laboratory with Accelerator Beams P. Muggli, University of Southern California, Los Angeles, CA 90089, USA S. Martins and L.O. Silva GoLP/Instituto de Plasmas e Fusao Nuclear Instituto Superior Tenico, Lisbon, Portugal Space-time overlap of SLAC FACET equal charge e - /e + for fireball beam Ultra-relativistic, neutral, e - /e + beam/plasma: No charge, no fields, no current!! The fireball beam is subject to the transverse, EM, current filamentation instability Relativistic neutral outflows collision with interstellar matter are ubiquitous CFI could play important role in afterglow of gamma ray bursts (GRBs), in the generation of magnetic fields and radiation Numerical simulations show that the instability saturates after only 10cm of plasma at n e =2.7x10 17 cm -3

33 Beam filaments Electron and positron beam filaments and plasma density perturbation Magnetic fields The instability generates magnetic fields and plasma density gradient that w be detected by Faraday rotation and Schlieren imaging. Measurements along the plasma will yield CFI evolution/growth rate The associated (jitter?) radiation will also be detected. Experiment will be proposed and will use FACET PWFA set up.

34 Study of Current Filamentation Instability of an Electron Beam in a Centimeter Long Capillary Plasma Brian Allen - University of Southern California Current Filamentation Instability (CFI): Basic, purely transverse plasma instability Results in breakup of the beam into narrow high current filament, enhances the generation of magnetic fields and generates radiation Occurs when r >>c/ pe and >>1 BNL-ATF: e - beam/capillary plasma discharge r =100 m, c/ pe =10 m, =110, n e =5x10 17 cm -3 Satisfies CFI criteria Simulations with QuickPIC: Filament size 4 µm Filament spacing 20 µm Both c/ pe 34

35 Study of Current Filamentation Instability of an Electron Beam in a Centimeter Long Capillary Plasma Brian Allen - University of Southern California BNL-ATF Allows independent control of beam and plasma Similar experiment/parameters to PWFA Experiment underway at ATF to characterize CFI Q=400pC Magnetic Energy (A.U.) Q=250pC Q=200pC Q=100pC Growth in magnetic energy as a function of plasma length Propagation Distance (cm)

36 Preventing Ion Motion using High Temperature Presenter: Reza Gholizadeh (USC) 2 2 i K 2 b 3 d d 2 2 ne b Kb 2 Mc vx kt B i c c M ions Electron beam Envelope Equation for Plasma ions Emittance of Ion Beam K b 4 2 i 2 Ne T b k B z 5 Matching Condition ev Initial Temperature for no Ion Motion

37 Normalized Ion Density Cold Plasma T=20 KeV T=40 KeV T=200 KeV T=340 KeV Ions ' (micron) 40 QuickPIC simulation results. Focusing Field (MV/m) Cold Plasma T=20 KeV T=40 KeV T=200 KeV T=340 KeV x (microns)

38 Injection and Capture

39 Presenter: S. Austin Yi

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41 An Experiment to Demonstrate Plasma Wave Bunching of a Low Energy Injected Electron Beam James Rosenzweig, Atsushi Fukasawa, Bernhard Hidding, Pietro Musumeci, Pardis Niknejadi, Brendan O'Shea, Diktys Stratakis, Oliver William (UCLA Physics and Astronomy), Sergei Tochitsky, Chan Joshi (UCLA EE) Investigate proposal by van Dijk to capture e-beam injected ahead of LWFA pulse 1D analysis inspires: 3D study for Neptune expt.

42 Neptune scenario >15 TW laser, 3 ps FWHM, p =1.8 mm, n 0 =3E14/cc Focus to w=280 micron (a=0.5) Low energy beam (2.5 MeV) to get slippage, capture Notable 3D effects in wakes Test bunching; CTR diagnostic Wakefield from VORPAL Hamiltonian model for dynamics VORPAL bunching (x10)

43 Thanks to all!