Ion acceleration: Strategy for 100 GeV proton beam

Transcription

1 IZEST Bordeaux, France Ion acceleration: Strategy for 100 GeV proton beam X.Q.Yan State Key Lab of Nuclear Physics and Technology, Peking Univeristy, China Center of Applied Physics and Technology X.Yan@pku.edu.cn

2 Acknowledgements PKU: J.E.Chen, X.T.He, C.Lin, S.Zhao, J.Zhu, H.Z.Fu, Y.R.Lu, B.Liu, H.C.Wu, H.Y.Wang, F.L.Zheng MPQ/LMU: T.Tajima, J. Meyer-ter-Vehn, D.Habs, J.Schreiber, W.J.Ma IZEST/ILE: G.Mourou LANL: M. Hegelich, L.Yin, H.C.Wu SHJU/IOP: J.Zhang, Z.M.Sheng, Y.T.Li

3 outline 1. Two dominant mechanisms: TNSA and RPA 2. Challenges of RPA and Laser plasma lens 3. Mono-energetic and Collimated 100GeV proton beam generation in multi-stage acceleration 4. Perspective of proton acceleration 5. Conclusion

4 Target Normal Sheath Acceleration (TNSA) Ions are much more heavier than electrons, the plasma wake field can hardly trap and accelerate slow ions! They are mainly accelerated from solid targets by TNSA so far. Electric Field: >TV/m!!! Acc length is only few microns Phys. Rev. Lett. 85, 2945 (2000). 4

5 Target Normal Sheath Acceleration (TNSA) Maximum proton energy 60 MeV in 2000 and 68 MeV in 2011, moreover the spectrum is still exponential! Phys. Rev. Lett. 85, 2945 (2000). Phys. Plasmas 18, (2011) 5

6 Proton energy scaling in TNSA J. FUCHS, nature physics,2, 48,2006 Challenges: proton energy is proportional to square root of laser intensity!

7 Radiation Pressure Acceleration Esirkempov, et al., PRL 92, (2004) A. Macchi, et al, PRL 94, (2005) X.Zhang, et al, PoP, 14, (2007) X.Q.Yan et al, PRL, 100, (2008) Rykovanov, et al, NJP. 10, (2008) Klimo et al, PRST 11, (2008) Robinson et al, NJP 2008 A. Macchi, et al, PRL (2009). M. Chen et al., PRL 103, (2009). A.Henig et al. PRL 103, (2009) B.Qiao et al., PRL 102, (2009) X.Q. Yan, et al., PRL. 103, (2009) S.Bulanov, et al, PRL 104, (2010) D.Jung,et al. PRL 107, (2011) p x RPA (CP + nanometers) Mono-energetic ion beam 0.45 t=50t L x/ L Synchrotron oscillation 7

8 N(Arb.Unit) Phase stability (1944) p x Phase space (x~p x ) 0.16 t=18t L A B Photo by U. Amaldi Particles are compressed in the phase space! a) x/ L 1D 2D Energy(MeV)

9 N(Arb.Unit) Phase Stable Acceleration regime a ~ ( n / n ) D/ 0 ( x Phase space (x~p c L A p x 0.16 t=18t L A B W W r 2 0 / p l / p r s r B a) x/ L 1D 2D xe /,(0 ) 1 Exd 0 xd E 4 nd 0 0 EExdldxdl (1( )/,( ) x20 s s ( 2008 ) X.Q.Yan et al, PRL 100, Energy(MeV)

10 Phase motion is harmonic Motion equations: d x q E 2 i i 0 (1 ( x ) / ) 2 3 i d ls dt mi 2 dxr qe r 0 (1 ( x ) / ) 2 3 r d ls dt mi p x 0.16 t=18t L x/ L Phase motion equation: 2, 2 qie m l i s sin( t) or proton/ions ~1, The phase motion is harmonic with frequency The energy spread is derived: w / w 2 / r 0 p r

11 Sailboat Sail model PSA Electron--- Sail Proton--- Boat Laser ---Wind PRL 102, (2009) ( 2008 ) PRL 100,

12 Conversion Efficiency (CE) CE=1- ~100%

13 RPA in 2D/3D situation Super Gaussian pulse for solid density target, I>10^23W/cm2 B.Qiao et al., PRL 102, (2009)

14 Arb.Unit Self-organizing GeV proton in Phase Stable regime (a) t=16 I~10^22W/cm2 (b) t=36 e r ~0.5 mm.mrad (c) t=42 60 t=40 T t=50 T t=54 T t=58 T (b) X.Q.Yan, W.H.C, Z.M.Sheng,J.E.Chen, J.MtV, et al., PRL, 103, , (2009) 14

15 Demonstration of RPA (I) a ~ ( n / n ) D/ 0 c L I~5*10^19W/cm2,5nm DLC foil 13MeV proton; 30MeV carbon CE~10%

16 Demonstration of RPA (II) a ~ ( n / n ) D/ 0 c L I~10^20W/cm2 5nm DLC foil 40MeV carbon

17 Optimum thickness of DLC is 5nm a ~ ( n / n ) D/ 0 c L RPA has rigorous request on laser contrast!

18 2. Challenges of RPA and Laser plasma lens

19 High contrast? Ultrathin solid target

20 Plasma mirror Nature Physics, Vol 3, (2007)

21 Laser Plasmas lens Plasma Lens Ultrathin solid target H.Y.Wang, et al., PRL 107, (2011).

22 Relativistic Magnetic Self-Channeling of Light in Near-Critical Plasma A. Pukhov* and J. Meyer-ter-Vehn, 76, 3975, 1996

23 Focus and steepening at the same time Near critical plasma nm foil intensity 20 times higher Steepened!!!

24 After shaping before

25 Scaling law for plasma lens (I) H.Y.Wang, et al., PRL 107, (2011).

26 Scaling law for plasma lens (II) H.Y.Wang, et al., PRL 107, (2011).

27 Laser Plasmas lens Plasma Lens Ultrathin solid target H.Y.Wang, et al., PRL 107, (2011).

28 3. Mono-energetic and Collimated 100GeV proton beam by multi-stage acceleration

29 Arb.Unit Self-organizing GeV proton in Phase Stable regime (a) t=16 I~10^22W/cm2 (b) t=36 e r ~0.5 mm.mrad (c) t=42 60 t=40 T t=50 T t=54 T t=58 T (b) X.Q.Yan, W.H.C, Z.M.Sheng,J.E.Chen, J.MtV, et al., PRL, 103, , (2009) 29

30 Maximum Proton Energy (MeV) Scaling law of proton energy To generate 100GeV proton beam, I~10^24-25W/cm^2? 1000 E ~ max I E19 1E20 1E21 1E22 Laser intensity I (W/cm 2 ) T.Tajima, D.Habs, and X.Q.Yan. Review of Accelerator Science and Technology, 2( ),2009.

31 multi-stage acceleration (RPA+wakefield) matching condition: 31

32 500GeV proton predicted in 1D simulation 10^23 W/cm^2, 133fs, sub-tev proton beam F.L.Zheng, H.Y,Wang, X.Q.Yan, T.Tajima et al., Phys. Plasmas 19, (2012)

33 Positive ions are diverging in 2D wakefield Defocusing 33

34 Small target + underdense gas Laser I~10^22W/cm2 55fs underdense gas n e =0.15n c Proton-rich MLT foil, 0.5um, 20n c

35 twin wakes in 2D or donut in 3D Laser energy Electron density current <Ey-Bz> ( 2011 )submitted, X.T.He, X.Q.Yan, T.Tajima,, F.L.Zheng 35

36 Strong focusing, instead of defocusing in Bubble Focusing in twin wakes <Ey-Bz> Defocusing in bubble

37 Proton density Monoenergetic and collimated Proton beam Angular distribution Proton spectrum <10um 37

38 100GeV proton beam generation, 2D Simulation ~cm preformed channel 7GeV protons 2*2um2 Laser I 0 = 1.7e23 Nanofibre r=20um tao~50fs 70KJ Nanofibre R=0.5um n=3nc n0= 0.04nc,n(y) = 0.04*(1+(y/35e-06)^2)

39 nanofibre -> gap -> axial current -> focusing fields nanofibre induced ponderomotive potential gap axial current, from both nanowire and channel

40 100GeV proton beam Peak ~ 102GeV, E/E ~ 11% 4x17 um mm.mrad ±1.3

41 4. Perspective of Laser proton accelerator 1.Demonstration of 100MeV~1GeV proton with IZEST lasers 100MeV~1GeV 41

42 Theoretical prediction of >100MeV at ~10^20W/cm2 H.Y.Wang, et al., submitted (2012)

43 proton energy in plane of CDT plasma density ne and length D H.Y.Wang, et al., submitted (2012)

44 LAser Proton Accelerator(LAPA) at PKU 1)Cancer therapy 200TW~1PW 2)ICF fast ignion 3) Plasma diagnostic 4) Proton Imaging 5)Low energy injector 44

45 Target fabrication at PKU Nm self-standing foil target is one of key technology for ion acceleration! FCVA 5nm freestanding DLC foil 电阻蒸发镀膜机

46 Thickness measurement

47 Self standing nm DLC foil 5~50nm thickness:5nm aperture:1mm thickness :20nm aperture :3mm

48 Gas-fill cone target (GCT) H.Y.Wang et al., Phys. Plasmas 18, (2011)

49 100GeV Laser proton accelerator 1.Demonstration of 100MeV~1GeV proton 2. IZEST(PETAL), 100GeV proton ~100GeV proton ~1cm underdense gas 100MeV~1GeV IZEST(PETAL), 100GeV proton 49

50 5. conclusion Laser plasma lens can steepen and focus the laser beam at the same time, due to relativistic selffocusing and self phase modulation. Multi dimensional simulations show that tens~hundreds GeV collimated proton beam can be generated in a donut-channel! 2D simulations show that 70KJ laser energy is needed for generating 100GeV mono-energetic proton beam! Thanks for your attention!

51 Channel guiding is necessary for ultraintense laser pulse Refractive index:

52 Homogeneous versus Parabolic gas Homogeneous Parabolic density

53 DLC Target Manufacture System We have successfully manufactured Diamond-like Carbon (DLC) foil with thickness between 5~40nm. Coating DLC NaCl Film stripping Water Get out of water Frame Si Image of DLC foil DLC foil & NaCl layer Coating machining Measurement of atomic force microscope