Plasma Accelerators (III)--- Proton-driven plasma wakefield acceleration

Transcription

1 Cockcroft Institute Lectures on Accelerator Physics Plasma Accelerators (III)--- Proton-driven plasma wakefield acceleration 11/05/2015 Cockcroft Institute Lecture 1

2 Outline Why proton-driven PWFA Short proton bunch production AWAKE experiment at CERN Colliders based on PD-PWFA Summary 11/05/2015 Cockcroft Institute Lecture 2

3 List of people discussing project 11/05/2015 Cockcroft Institute Lecture 3

4 Motivation 11/05/2015 Cockcroft Institute Lecture 4

5 Energy gain E N 0.6 = 240(MeV/m) σ z (mm) 2 σ z Transformer ratio limit * R E witness max = drive Emax 2 for longitudinal symmetric bunch 11/05/2015 Cockcroft Institute Lecture 5

6 PWFA-based linear collider* *M. Hogan et al., Proceedings of PAC09 (TU1GRI01) *A. Seryi et al., Proceedings of PAC09 (WE6PFP081) 11/05/2015 Cockcroft Institute Lecture 6

7 Existing proton machines HERA TEVATRON LHC Circumference [km] Maximum energy [TeV] Energy spread [10-3 ] Bunch length [cm] Transverse emit. [10-9 π m rad] Particles per bunch [10 10 ] /05/2015 Cockcroft Institute Lecture 7

8 high energy proton beam as driver Hugh energy stored in current proton machines like Tevatron, HERA, SPS and LHC For example, the SPS/LHC beam carries significant stored energy for driving plasma waves SPS (450 GeV, 1.3e11 p/bunch) ~ 10 kj LHC (1 TeV, 1.15e11 p/bunch) ~ 20 kj LHC (7 TeV, 1.15e11 p/bunch) ~ 140 kj SLAC (50 GeV, 2e10 e-/bunch) ~ 0.1 kj However, the current proton bunches are quite longer to use as driver directly. Need much effort to compress the beam How to couple the energy of driver to the plasma and the witness beam efficiently? 11/05/2015 Cockcroft Institute Lecture 8

9 PWFA and PDPWA blow-out flow-in (p+) linear response beam nonlinear response 11/05/2015 Cockcroft Institute Lecture 9

10 Proton-driven PWFA* * A. Caldwell et al., Nature Physics 5, 363 (2009) 11/05/2015 Cockcroft Institute Lecture 10

11 Schematics of PD-PWFA A thin tube containing Li plasma is surrounded by quadrupole magnets with alternating polarity. The magnification shows the plasma bubble created by the proton bunch (red). The electron bunch (yellow) undergoing acceleration is located at the back of the bubble. Note that the dimensions are not to scale. * A. Caldwell et al., Nature Physics 5, 363 (2009) 11/05/2015 Cockcroft Institute Lecture 11

12 Parameter settings Symbol Value Drive Beam Protons in drive bunch [10 11 ] N p 1 Proton energy [TeV ] E p 1 Initial proton momentum spread σ p /p 0.1 Initial longitudinal spread [µm ] σ z 100 Initial angular spread [mrad ] σ θ 0.03 Initial bunch transverse size [mm ] σ X,Y 0.4 Witness Beam Electrons in witness bunch [10 10 ] N e 1.5 Energy of electrons [GeV ] E e 10 Plasma Parameters Free electron density [cm -3 ] n p Plasma wavelength [mm ] λ p 1.35 External Field Magnetic field gradient [T/m ] 1000 Magnetic length [m ] /05/2015 Cockcroft Institute Lecture 12

13 Simulations Fig.a-d), Simulation results for the unloaded (no witness bunch) case (a,b) and in the presence of a witness bunch (c,d). The witness bunch is seen as the black spot in the first wave bucket in d). d) also shows the driving proton bunch at the wavefront (red). e) The on-axis accelerating field of the plasma wave for the unloaded (blue curve) and loaded (red curve) cases. * A. Caldwell et al., Nature Physics 5, 363 (2009) 11/05/2015 Cockcroft Institute Lecture 13

14 Energy gain Simulation results 1 TeV 10 GeV phase 11/05/2015 Cockcroft Institute Lecture 14

15 Phase space of driver & witness Fig. a-h), Snapshots of the combined longitudinal phase space of the driver and the witness bunches (energy versus coordinate) (a d) and corresponding energy spectra (e h). The snapshots are taken at acceleration distances L=0, 150, 300, 450 m. The electrons are shown as blue points and the protons are depicted as red points. * A. Caldwell et al., Nature Physics 5, 363 (2009) 11/05/2015 Cockcroft Institute Lecture 15

16 Energy gain & energy spread 620 GeV beam can be obtained energy spread less than 1 % Fig. a,b), The mean electron energy in TeV (a) and the r.m.s. variation of the energy in the bunch as a percentage (b) as a function of the distance travelled in the plasma. * A. Caldwell et al., Nature Physics 5, 363 (2009) 11/05/2015 Cockcroft Institute Lecture 16

17 Simulation results Proton bunch can indeed to be used as the drive beam for exciting a large amplitude wakefield Proton-driven PWFA can bring a bunch of electrons to the energy frontier in only one stage. An unsolved questions, short beam! 11/05/2015 Cockcroft Institute Lecture 17

18 Short proton bunch production 11/05/2015 Cockcroft Institute Lecture 18

19 Magnetic bunch compression Tail ΔE/E (advance) -z Head (delay) lower energy trajectory center energy trajectory higher energy trajectory To compress a bunch longitudinally, trajectory in dispersive region must be shorter for tail of the bunch than it is for the head. 11/05/2015 Cockcroft Institute Lecture 19

20 Bunch compressor design z( s δ ( s For a thousand-fold compression, one stage compression looks infeasible We expect that the ring could compress the bunch by a factor of 10 and the rest will be realized via magnetic chicane 2 2 ) 1 = ) 0 R R 65 0 z( s 1 δ ( s 0 0 ) 1+ R = ) R R R R56 R65 = 0 δ 1 ΔE ev0 ω = = = z z E E βc 2 = 2 LB + ΔL B 3 56 θ R 65 R 56 1 z( s δ ( s 0 0 ) ) Value Bunch charge Proton energy [TeV] 1 Initial energy spread [%] 0.01 Initial bunch length [cm] 1.0 Final bunch length [μm] 165 RF frequency [MHz] Average gradient of RF [MV/m] 25 Required RF voltage [MV] 65,000 RF phase [degree] -102 Compression ratio ~60 Momentum compaction (MC) [m] -1.0 Second order of MC [m] 1.5 Bending angle of dipole [rad.] 0.05 Length of dipole [m] 14.3 Drift space between dipoles [m] Total BC length [m] 4131 Final beam energy [GeV] Final energy spread [%] /05/2015 Cockcroft Institute Lecture 20

21 Phase space of beam 4,0x10-4 0,04 2,0x10-4 0,02 dp/p 0,0 dp/p 0,00-2,0x ,02 a) Initial phase space -4,0x ,04-0,02 0,00 0,02 0,04 z / m 0,04 c) Final phase space -0,04-5,00x ,50x10-4 0,00 2,50x10-4 5,00x10-4 z / m 0,02 dp/p 0,00-0,02 b) Phase space after RF section -0,04-0,04-0,02 0,00 0,02 0,04 z / m G. Xia, A. Caldwell et al., Proceedings of PAC09 (FR5RFP011) 11/05/2015 Cockcroft Institute Lecture 21

22 Phase space of beam 0,04 b) c) 0,02 dp/p 0,00 a) -0,02 a) initial phase space b) phase space after RF c) phase space after bunch compressor -0,04-0,04-0,02 0,00 0,02 0,04 z / m G. Xia, A. Caldwell et al., Proceedings of PAC09 (FR5RFP011) 11/05/2015 Cockcroft Institute Lecture 22

23 Bunch length & energy spread Fitting data show that the bunch length of 170 micron and the relative energy spread of 9e-3 can be achieved. A. Caldwell, K. Lotov, A. Pukhov, G. Xia, Plasma Phys. Control. Fusion 53 (2011) /05/2015 Cockcroft Institute Lecture 23

24 Plasma wakefield slicing via modulation SPS beam at 5m 1e14 cm -3 density modulation effect on-axis (X = 0) beam density profile after 5 m propagation in plasma G. Xia, et al., AIP Proceedings of Advanced Accelerators Concepts 2010, G. Xia, F.Zimmermann, et al., Proceedings of PAC09, (FR5RFP004) 11/05/2015 Cockcroft Institute Lecture 24

25 Demonstration experiment at CERN PS (East Hall Area) and SPS (West Area) could be used for our demonstration experiment 11/05/2015 Cockcroft Institute Lecture 25

26 Long bunch modulation by wakefield 11/05/2015 Cockcroft Institute Lecture 26 A. Pukhov

27 SPS beam for a test experiment Super Proton Synchrotron-SPS Momentum [GeV/c] 450 Maximum protons/bunch [10 11 ] 1.15 rms bunch length [cm] 12 rms energy spread [10-4 ] 2.8 rms transverse emittance [µm] 3.5 dipole Bunch spacing [ns] 25 beam dump steep tunnel I.Efthymiopoulos, EN/MEF - CERN 11/05/2015 Cockcroft Institute Lecture 27

28 SPS beam for a test experiment large space available for SPS tunnel The SPS/LHC proton bunch has excellent properties: Very stiff beam: can drive plasma without too much beam deterioration. Well controlled and maintained (for LHC, CNGS, HiRadMat, ). Variable in intensity (2e9-3.0e11) and emittance. Carries significant stored energy for driving plasma waves: The issue is how to couple the proton energy to the plasma (via modulation): CERN proton bunches are very long (120 mm), compared to the electron bunches used at SLAC (< 0.1 mm). Plasma wavelength is at the 1 mm scale. How do we couple the proton beam energy into the plasma and then to the witness electron beam? 11/05/2015 Cockcroft Institute Lecture 28

29 Codes benchmarking Various particle-in-cell (PIC) codes are used to benchmark the results based on the same parameter set. Presently they show very good agreement 11/05/2015 Cockcroft Institute Lecture 29

30 Seeding the instability n b E ac c E focu s n p For SPS half-cut beam, at plasma density n p =10 14 cm -3 (λ p 3.33 mm) A strong beam density modulation is observed, A nice wakefield structure is excited and the wakefield amplitude is around 100 MV/m at 5 m plasma. 11/05/2015 Cockcroft Institute Lecture VLPL results from A. Pukhov 30

31 Simulations of SPS beam-driven PWFA Beam density modulation Maximum longitudinal e field is ~120 MV/m 11/05/2015 Cockcroft Institute Lecture 31 G. Xia, et al.,aip Proceedings of Advanced Accelerators Concepts 2010,

32 Simulations of SPS beam-driven PWFA Simulation from 2D OSIRIS nominal SPS beam Bunch population, N p 1.15x10 11 Bunch length, σ z 12 cm Beam radius,σ x,y 200 μm Beam energy, E 450 GeV Energy spread, de/e 0.03% Bunch population, N p 3x10 11 Bunch length, σ z 8.5 cm Beam radius,σ x,y 200 μm Beam energy, E 450 GeV Energy spread, de/e 0.04% Normalized emittance, ε x,y 3 μm Normalized emittance, ε x,y 2 μm Angular spread, σ θ 0.02 mrad Angular spread, σ θ 0.02 mrad 11/05/2015 Cockcroft Institute Lecture 32 G. Xia, et al, Proceedings of PAC11 (MOP108), New York, 2011

33 Electron acceleration n p =1e14 cm -3 n p =7e14 cm -3 VLPL3D hydro-dynamic code (A. Pukhov) 10 MeV continuous e- beam to sample the wakefield 11/05/2015 Cockcroft Institute Lecture 33

34 Electron acceleration Plasma density in use: 7x10 14 cm -3 SPS-LHC SPS-Opt. Beam energy [GeV] Bunch population [10 11 ] Beam radius [μm] Angular spread [mrad] Normalized emittance [μm] Bunch length [cm] Energy spread [%] /05/2015 Cockcroft Institute Lecture 34 G. Xia, et al, Proceedings of PAC11 (TUOBN5), New York, 2011

35 Demonstration experiment at CERN 11/05/2015 Cockcroft Institute Lecture 35

36 Demonstration experiment at CERN Kick-off meeting 2009 old beam lines beam dump /05/2015 Cockcroft Institute Lecture 36 G. Xia et al, Proceedings of PAC11 (TUOBN5), New York, 2011

37 CERN s interest "CERN is very interested in following and participating in novel acceleration techniques, and has as a first step agreed to make protons available for the study of proton-driven plasma wakefield acceleration." 11/05/2015 Cockcroft Institute Lecture 37

38 Vancouver Glasgow Manchester London Lisbon Oslo Hamburg, Dusseldorf Greifswald Munich CERN Novosibirsk 11/05/2015 Cockcroft Institute Lecture 38

39 In 2011: protons to LHC protons to CERN s Non-LHC Experiments and Test Facilities LHC: 7 TeV SPS: 400/450 GeV BOOSTER: 1.4 GeV PS: 24 GeV 11/05/2015 Cockcroft Institute Lecture 39

40 GeV Variation of driver energy at constant normalized emittance SPS-AWAKE parameters K. Lotov et al., Physics of Plasma, 21, (201 11/05/2015 Cockcroft Institute Lecture 40

41 SPS Beam at 400 GeV/c SPS: 400 GeV AWAKE will be installed in the CNGS, CERN Neutrinos to Gran Sasso, experimental facility. CNGS physics program finished in /05/2015 Cockcroft Institute Lecture 41

42 Proton beam radius Wakefield amplitude 5e11 4e11 3.5e11 3e11 1.5e11 2.5e11 2e11 Wakefield amplitude 0.1 mm 0.15 mm 0.2 mm 0.25 mm 0.3 mm 0.5 mm 1.15e11 The baseline regime is close to the limit (~40% of wave-breaking field) Further increase of population does not result in proportional field growth. Length along plasma cell 0.05 mm Length along plasma cell Wide beams are not dense enough to drive the wave to the limiting field. Narrow beams are quickly diverging due to the transverse emittance. Baseline radius is the optimum one for this emittance. 11/05/2015 Cockcroft Institute Lecture K. Lotov et al., Physics of Plasma, 21, (2014) 42

43 σ σ μ Δ Long proton beam σ z = 12cm! Compare with plasma wavelength of λ = 1mm. Experiment based on Self-Modulation Instability! Self-modulation instability of the proton beam: modulation of a long (SPS) beam in a series of micro-bunches with a spacing of the plasma wavelength. 11/05/2015 Cockcroft Institute Lecture 43

44 α Φ max 5e15 3e15 2e15 1e15 1.5e15 Plasma density 7e14 5e14 3e14 2e14 λ λ σ Δ 11/05/2015 Cockcroft Institute Lecture 44

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46 (Rb) (Cs) 197 (Au) 39.9 (K) 24.3 (Mg) 6.9 (Li) 1 (H) Rubidium is heavy enough to have no problems with ion motion 11/05/2015 Cockcroft Institute Lecture 46

47 Φ Required: Δn/n = ΔT/T /05/2015 Cockcroft Institute Lecture 47

48 3m prototype at MPI Munich 11/05/2015 Cockcroft Institute Lecture 48

49 11/05/2015 Cockcroft Institute Lecture 49

50 σ λ σ Laser system in MPI, Munich Summary: 4.5 TW Laser for ionization and seeding 11/05/2015 Cockcroft Institute Lecture 50

51 plasma gas proton bunch laser pulse λ p = 1.2 mm N. Kumar, A. Pukhov, K. Lotov, Phys. Rev. Letters (2010): Self-modulated proton bunch resonantly driving plasma wakefields. 11/05/2015 Cockcroft Institute Lecture 51

52 Laser SPS protons p plasma 10m plasma cell gas proton bunch Proton diagnostics OTR, CTR, TCTR Laser dump Proton beam dump laser pulse Self-modulated proton bunch resonantly driving plasma wakefields. radius (r) 8.3 meters r Propagation direction pe plasma Plasma electron ] e0 density ρ [n Proton beam density ρ beam [n e0 ] Distance in beam (z) J. Vieira et al PoP (2012) 11/05/2015 Cockcroft Institute Lecture 52

53 σ p ~ 400 ps OTR 4 ps CTR & TCTR Laser SPS protons p SMI 10m Laser dump BTV Laser dump BTV Proton beam dump 11/05/2015 Cockcroft Institute Lecture 53

54 Which energy? Position along the proton bunch Area (grey) where wakefields are both accelerating and focusing for the witness electrons Plasma cell length 11/05/2015 Cockcroft Institute Lecture 54

55 - σ σ μ Δ 11/05/2015 Cockcroft Institute Lecture 55

56 2 black points injected electrons, false colors wakefield potential K. Lotov, LCODE r, mm 0-17 ξ, cm Electrons are trapped from the very beginning by the wakefield Trapped electrons make several synchrotron oscillations in their potential wells After z=4 m the wakefield moves forward in the light velocity frame 11/05/2015 Cockcroft Institute Lecture 56

57 λ μ e-beam diagnostics Klystron from CTF3 1m booster linac (Cockcroft) Incident, Reflected Power and phase electron beam line Laser +Diagnostics FCT Emittance Incident, Reflected, transmitted Power Matching triplet Spectrometer E, ΔE MTV BPR MS BPR BPR F C RF GUN Corrector VP I Accelerator MTV, Emittance Length ~ 4 m 11/05/2015 Cockcroft Institute Lecture 57

58 Magnet: 15 ton, 1.84 T, 3.80 Tm, L=1670 mm, W=1740 mm p e - e - Camera Dispersed electron impact on scintillator screen. Resulting light collected with intensified CCD camera. Scintillator screen 11/05/2015 Cockcroft Institute Lecture 58

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60 SPS protons e - spectrometer Laser RF gun p e - SMI plasma gas proton bunch electron bunch laser pulse 10m Acceleration Proton diagnostics OTR, CTR, TCTR Laser dump Proton beam dump E 11/05/2015 Cockcroft Institute Lecture r' 60

61 n p n e (a) z 1.2 (b) stepped-up uniform z, m Plasma density profile Maximum wakefield amplitude 11/05/2015 Cockcroft Institute Lecture E, GV/m z,max

62 11/05/2015 Cockcroft Institute Lecture 62

63 SPS LHC AWAKE CERN 11/05/2015 Cockcroft Institute Lecture 63

64 protons SPS AWAKE experiment LHC ~1100m dump 11/05/2015 Cockcroft Institute Lecture 64

65 Laser SPS protons RF gun p laser room e - SMI Acceleration Proton diagnostics OTR, CTR, TCTR e - spectrometer Laser dump electron source, klystron electron beam line Proton beam dump plasma cell, 10m diagnostics protons towards proton beam dump proton beam-line proton-lasermerging 11/05/2015 Cockcroft Institute Lecture AWAKE experiment 65

66 Change of the proton beam line only in the downstream part (~80m) laser room electron source, klystron electron beam line plasma cell, 10m diagnostics proton beam-line proton-lasermerging 750m proton beam line Displace existing magnets of the final focusing to fulfill optics requirements at plasma cell CNGS Layout AWAKE Layout Laser-proton merging 20m upstream the plasma cell Move existing dipole and 4 additional dipoles to create a chicane for the laser mirror integration. 11/05/2015 Cockcroft Institute Lecture 66

67 New tunnel 11/05/2015 Cockcroft Institute Lecture 67

68 laser room electron source, klystron electron beam line plasma cell, 10m diagnostics proton beam-line proton-lasermerging Plasma cell 11/05/2015 Electron Cockcroft beam envelope Institute Lecture (H, V) 68

69 plasma cell, 10m diagnostics 69 electron source, klystron electron beam line proton-lasermerging proton beam-line laser room Excavation June October /05/2015 Cockcroft Institute Lecture

70 plasma cell, 10m diagnostics 70 electron source, klystron electron beam line proton-lasermerging proton beam-line laser room 11/05/2015 Cockcroft Institute Lecture

71 Electron bunch (1σ~4ps) Plasma gas proton bunch (1σ ~400ps) laser pulse (100fs) σ 11/05/2015 Cockcroft Institute Lecture 71

72 2016 Phase 1: Self-Modulation Instability physics Phase 2: Electron acceleration physics 11/05/2015 Cockcroft Institute Lecture 72

73 Collider based on proton driven PWFA Concept for high repetition rate of proton driven plasma wakefield acceleration 3 ring + injectors + recovery V. Yakimenko, BNL, T. Katsouleas, Duke, LAPW09 11/05/2015 Cockcroft Institute Lecture 73

74 Luminosity IP beam sizes: 60 nm (horizontal) and 0.7 nm (vertical) L= cm -2 s -1 11/05/2015 Cockcroft Institute Lecture 74

75 Phase slippage δ = πl 1 1 πl M 2 P c 4 λ p γ 1i γ 1 f γ 2i γ 2 f λ p E driver,i E driver, f L 1 E driver,i E driver, f λ 2 M 2 P c 4 p 300 m for E driver,i =1TeV,E driver, f = 0.5TeV,λ =1mm 11/05/2015 Cockcroft Institute Lecture 75

76 Plasma density variation LHC beam w. plasma density ramp ~ 900 MV/m field propagates stably for 200 m! Increasing the plasma density properly at the moment of developed instability, the wave shift with respect to the main body of the beam will be stopped and one can obtain a stable bunch train that propagates in plasma for a long distance (K. Lotov) 11/05/2015 Cockcroft Institute Lecture 76

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79 200 MHz RF system in the SPS: RF-structure quality factor Q = 200, filling time = 600 ns (1 beam turn in SPS takes 23 μs) Barrier bucket experiments in SPS: Beam current 8 μs RF Voltage 11/05/2015 Cockcroft Institute Lecture 79 From presentation by E. Shaposhnikova et. al.:

80 In order to suppress multibunch instabilities longitudinal emittance in the SPS is blown up by a factor of 2. In the single bunch mode the longitudinal emittance blowup can be switched off. SPSoptimum (single bunch) SPSoptimum + bunch rotation Low emittance + bunch rotation SPS-LHC 11/05/2015 Cockcroft Institute Lecture 80

81 Multi-TeV lepton collider at LHC e + IP e - (K. Lotov) 11/05/2015 Cockcroft Institute Lecture 81

82 J. Plasma Physics: page 1 of 7. c Cambridge University Press 2012 doi: /s A proposed demonstration of an experiment of proton-driven plasma wakefield acceleration based on CERN SPS G. X I A 1, R. ASSMANN 2, R. A. FONSECA 3,C.HUANG 4, W. MORI 5, L. O. S I L V A 3, J. VIEIRA 3, F. ZIMMERMANN 2 and P. MUGGLI 1 for the PPWFA Collaboration 1 Max Planck Institute for Physics, Munich, Germany (xiaguo@mpp.mpg.de) 2 CERN, Geneva, Switzerland 3 GoLP/Instituto de Plasmas e Fusao Nuclear-Laboratório Associado, IST, Lisboa, Portugal 4 Los Alamos National Laboratory, Los Alamos, NM, USA 5 University of California, Los Angeles, CA, USA (Received 20 September 2011; accepted 2 January 2012) 11/05/2015 Cockcroft Institute Lecture 82

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84 Wide range of energy acceptance from tens of MeV to more than 2 GeV 11/05/2015 Cockcroft Institute Lecture 84

85 Specifications for AWAKE e- beam.

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87 11/05/2015 Cockcroft Institute Lecture 87

88 (K. Lotov) An e+ e- collider Contents lists available at ScienceDirect Nuclear Instruments and Methods in Physics Research A journal homepage: Collider design issues based on proton-driven plasma wakefield acceleration G. Xia a,b,n, O. Mete a,b, A. Aimidula b,c, C.P. Welsch b,c, S. Chattopadhyay a,b,c, S. Mandry d, M. Wing d,e a School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom b The Cockcroft Institute, Sci-Tech Daresbury, Daresbury, Warrington, United Kingdom c The University of Liverpool, Liverpool, United Kingdom d Department of Physics and Astronomy, University College London, London, United Kingdom e Deutsche Elektronen-Synchrotron DESY, Hamburg, Germany An e-p collider article info Keywords: PDPWA Colliders Self-modulation instability Dephasing 11/05/2015 Cockcroft Institute Lecture abstract Recent simulations have shown that a high-energy proton bunch can excite strong plasma wakefields and accelerate a bunch of electrons to the energy frontier in a single stage of acceleration. It therefore paves the way towards a compact future collider design using the proton beams from existing highenergy proton machines, e.g. Tevatron or the LHC. This paper addresses some key issues in designing a compact electron positron linear collider and an electron proton collider based on the existing CERN accelerator infrastructure. & 2013 Elsevier B.V. All rights reserved. 88

89 Future collider based on PD-PWFA An e+ e- collider An e-p collider Contents lists available at ScienceDirect Nuclear Instruments and Methods in Physics Research A journal homepage: accelerating gradient >1 GV/m Collider design issues based on proton-driven plasma wakefield acceleration G. Xia a,b,n, O. Mete a,b, A. Aimidula b,c, C.P. Welsch b,c, S. Chattopadhyay a,b,c, S. Mandry d, M. Wing d,e a School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom b The Cockcroft Institute, Sci-Tech Daresbury, Daresbury, Warrington, United Kingdom c The University of Liverpool, Liverpool, United Kingdom d Department of Physics and Astronomy, University College London, London, United Kingdom e Deutsche Elektronen-Synchrotron DESY, Hamburg, Germany article info abstract Keywords: PDPWA Colliders Self-modulation instability Dephasing Recent simulations have shown that a high-energy proton bunch can excite strong plasma wakefields and accelerate a bunch of electrons to the energy frontier in a single stage of acceleration. It therefore paves the way towards a compact future collider design using the proton beams from existing highenergy proton machines, e.g. Tevatron or the LHC. This paper addresses some key issues in designing a compact electron positron linear collider and an electron proton collider based on the existing CERN accelerator infrastructure. & 2013 Elsevier B.V. All rights reserved. 11/05/2015 Cockcroft Institute Lecture 89

90 AWAKE is the first proton-driven plasma wakefield acceleration in the world. It is also the first beam driven plasma wakefield acceleration experiment in Europe. AWAKE experiment will study the self modulated proton driven plasma wakefield acceleration; Proton beam from CNGS beam line will be used for the first experiment in the end of The first experiment goal is to demonstrate 1 GeV electron energy 10 m plasma, m plasma as the second step; The AWAKE experiment at CERN will shed light on a future compact Higgs factory or next generation energy frontier collider design. UK is the strong partner to the AWAKE project and give key contributions to the experiment, e.g. the discharge plasma source, diagnostics, simulations, electron injector, energy spectrometer, etc. The collaborated institutes include: CI, UCL, IC, RAL, JAI, Strathclyde University, etc. 11/05/2015 Cockcroft Institute Lecture 90

91 Phase slippage d d Δd 2 ( γ m c ) d i i dt d γ emec dt 2 ( ) ( γ m v ) i i i dt emev dt ( γ ) = mec ee 2 acc e = qe = ee = qe = qe dec acc dec v v acc e i Δ m c i m c 2 m ec γ e γ e0 mie γ i γ i ( v v ) dt = + T 0 d = e i 0 e Eacc meq Edec i i0 G. Xia et al., IPAC11 (WEPZ024) 11/05/2015 Cockcroft Institute Lecture 91 ( ) 2 2 γ i 1 γ i0 1 = qedect ( ) 2 2 γ 1 γ 1 ee T e e e0 = 2 2 ( γ )( ) ( ) ( )( ) e 1 γ e 1 γ 0 i γ i0 γ e γ e γ i 1 γ i0 1 γ e γ e0 m c ee e For γ e >> γ Δd i ( γ e γ e0) 2 acc 1 acc ( γ γ ) ( ) i i0 2 2 γ 1 γ 1

92 Phase slippage δ = k p Δd ee acc 1 / m cω e p ( γ γ ) e e0 ( γ γ ) ( ) i i γ i 1 γ i , γ e γ 0 10 e 6 phase slippage delta=pi gamma_i Phase slippage of a 1 TeV proton beam vs. gamma_i of the proton beam. G. Xia et al., IPAC11 (WEPZ024) 11/05/2015 Cockcroft Institute Lecture 92

93 Plasma cells 11/05/2015 Cockcroft Institute Lecture 93

94 Plasma cells 11/05/2015 Cockcroft Institute Lecture 94

95 Status and outlook AWAKE experiment will be the first proton-driven plasma wakefield accelerator worldwide Simulation shows that working in self-modulation regime, SPS beam can excite the field around ~ 1 GV/m with a high density plasma. Future experiment will be carried out based upon the first round experiments for even higher energy electron beam acceleration AWAKE experiment will give input to the future design for a compact, more affordable, multi-tev lepton collider. 11/05/2015 Cockcroft Institute Lecture 95

96 Thanks to Edda for many nice pictures! Thanks for your attention! 11/05/2015 Cockcroft Institute Lecture 96