Design of the Thomson Source at SPARC/ PLASMONX for incoherent and coherent X-rays

Transcription

1 Design of the Thomson Source at SPARC/ PLASMONX for incoherent and coherent X-rays Luca Serafini - INFN/MI - on behalf of SPARC & PLASMONX Team The PLASMON-X Project: a marriage between the SPARC high brightness electron beam and a high intensity laser beam Design and acquisition of a 2 TW Ti:Sa laser system for Plasma and IFEL acceleration exp. and a Thomson Source for monochromatic X-rays

2 Design of the Thomson Source at SPARC/ PLASMONX for incoherent and coherent X-rays Luca Serafini - INFN/MI - on behalf of SPARC & PLASMONX Team The PLASMON-X Project: a marriage between the SPARC high brightness electron beam and a high intensity laser beam Design and acquisition of a 2 TW Ti:Sa laser system for Plasma and IFEL acceleration exp. and a Thomson Source for monochromatic X-rays Coherent X-Rays at 1 Å from Thomson Sources as classical SASE-FELs or Quantum FELs (see also Maroli s and Piovella s talks in WG3)

3 Design of the Thomson Source at SPARC/ PLASMONX for incoherent and coherent X-rays Luca Serafini - INFN/MI - on behalf of SPARC & PLASMONX Team The PLASMON-X Project: a marriage between the SPARC high brightness electron beam and a high intensity laser beam Design and acquisition of a 2 TW Ti:Sa laser system for Plasma and IFEL acceleration exp. and a Thomson Source for monochromatic X-rays Coherent X-Rays at 1 Å from Thomson Sources as classical SASE-FELs or Quantum FELs (see also Maroli s and Piovella s talks in WG3)

4 (PLasma Acceleration at Sparc & MONochromatic X-rays) IS BASED ON THE MARRIAGE BETWEEN: High Brightness Electron Beams (from 1 s fs to a few ps bunch length) B n cq b A > 1 15 σ z ε nx ε ny m 2 rad 2 High Intensity Laser Beams (3-1 fs pulses) I > 1 19 W cm 2

5 IS THE FIRST INGREDIENT Under INFN responsibility (see also Daniele Filippetto s talk in WG4) Under ENEA responsibility

6 IS THE FIRST INGREDIENT Under INFN responsibility (see also Daniele Filippetto s talk in WG4) Under ENEA responsibility GOALS Generation of 3-15 MeV e - beams (Q, σ t, ε n, Δγ/γ) Phase 1) 1 nc, 3 ps, 1 μm, 1-3 Phase 2) 1 nc, 3 fs, 2 μm, PLASMONX) 2 pc, 6 fs,.3 μm,

7 Frascati Laser for Acceleration and Multidisciplinary Experiments (FLAME) SECOND INGREDIENT

8 MODULATOR & KLYSTRON HALL ACCELERATOR UNDERGROUND BUNKER CONTROL ROOM 15 m 36 m SPARC Building Complex PHOTOCATHODE DRIVE LASER CLEAN ROOM

9 Section view HILL Top view HILL Canvas Tent Storage Area FLAME SPARC bunker Lab. 1TW New building SPARC bunker SPARC Control room LWFA with self-injection + Thomson scattering LWFA with external injection + Thomson scattering

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11 Type Wavelength Delivered energy Duration Contrast Phase 1 CPA Ti:Sa Phase 2 CPA Ti:Sa with OPCPA.8 micron 5J 5fs >1 6.8 micron 5J 3fs >1 8

12 Schematic layout Photoinjector solenoid RF sections quadrupoles dipoles RF deflector collimator 25º 25º 1.5m 11º 1. m 5.4 m Diagnostic 14.5 m 1-6 Undulator modules

13 .6 HBUNCH.OUT 3 HBUNCH.OUT.5 sigma_z_[mm] sigma_x_[mm] 2.5 enx_[um] dg/g_[%] sigma_z_[mm] enx_[um] Z_[m] Q = 2 pc Z_[m] slight focusing after compression σ z =25 μm, Δγ/γ =.2%, ε nx <.3 μm I_[A] I_[A] T_[MeV] HBUNCH.OUT elz_[kevmm] HBUNCH.OUT elz_[kevmm] Z_[m] Z_[m] M. Ferrario, ICFA LBI-LPA 25 Workshop, Taipei

14 Bunch slicing Q = 1nC ==> 25pC Lb=1 ps ==> 1 fs σx =.5 mm ==> 5 μm Δγ/γ <.2% C. Vaccarezza et al., EPAC-4

15 beam energy distribution at start/end of the beam line start end 6 fs bunch (initially uncompressed) -> 1 fs with RF compression, i.e. by combining velocity bunching and bunch-slicing

16 Experimental set-up for the generation of tunable X-ray radiation via Thomson scattering of optical photons by relativistic electron bunches

17 THOMSON BACK-SCATTERING ν T = ν 1 β cosα L 1 β cosθ ν 4γ 2 1+ θ 2 γ 2 4γ 2 ν for α L = π and θ <<1 or θ = e - (1 GeV); λ =1µm, E =1.24 ev λ T =6 x1-8 µm, E T =2 MeV e - (2 MeV); λ =1µm, E =1.24 ev λ T =1.56 x1-6 µm, E T =8 KeV e - (29 MeV); λ =.8µm, E =1.5 ev λ T =.5 x1-4 µm, E T =2 KeV

18 25 best result (1nC Solenoid lens) Beam energy [MeV] z [m] Long.emit.[KeV-mm] rms en.-spread [KeV] x-rms beam spot [mm] 2, 1,5 1,,5, z [m] 2, 1,5 1,,5, rms norm. transv. emitt. [mm-mrad] x-rms beam spot [mm],2,16,12,8,4, 12,28 12,285 12,29 12,295 z [m] In the 25 simulation (autumn), playing especially with the injection phase of the II TW structure (involved in the linear correlation correction) have been possible obtain a bunch of about 3ps (~1mm) shorter, with a denser core

19 Angular and spectral distribution of the TS radiation in the case of an unguided 3 ps laser pulse (12.5 µm beam waist) Incoherent spontaneous radiation QuickTime and a TIFF (Uncompressed) decompressor are needed to see this picture.

20 High Flux operation mode

21 High Flux operation mode Bunch 2.5nC 8ps long (full size) 13μm rms tr. Size 1.5 mm mrad norm emittance.1% energy spread Current best working point TEM 5J in 6ps w = 15 μm Pulse

22 22%FWHM 5% FWHM

23 QuickTime and a TIFF (Uncompressed) decompressor are needed to see this picture.

24 QuickTime and a TIFF (Uncompressed) decompressor are needed to see this picture.

25 Brilliance of X-ray radiation sources λ (nm) SASE-FELs will allow an unprecedented upgrade in Source Brilliance TTF SPARX Covering from the VUV to the 1 Å X-ray spectral range: new Research Frontiers PLASMON-X Compact Thomson Sources extend SR to hard X-ray range allowing Advanced Radiological Imaging inside Hospitals

26 FEL resonance condition λ = λ w ( 2 1+ a ) w (magnetostatic wiggler ) 2γ 2 Example : for λ=1a, λ w =1cm, E=3.5GeV λ = λ pump ( 2 1+ a ) w (electromagnetic wiggler ) 4γ 2 Example : for λ=1a, λ pump =1μm, E=25MeV

27 Toward Coherent X-rays: exploring coherent emission mechanisms (FEL-like) in Thomson Sources FEL-Conf. 25

28 ( Conditions to operate a Thomson Source in FEL mode λ R = λ 1+ a 2 ) 4γ 2 τ 2σ β τ R

29 ( Conditions to operate a Thomson Source in FEL mode λ R = λ 1+ a 2 ) 4γ 2 τ 2σ 2R β Z τ R

30 ( Conditions to operate a Thomson Source in FEL mode λ R = λ 1+ a 2 ) 4γ 2 τ 2σ 2R β Z τ R

31 ( Conditions to operate a Thomson Source in FEL mode λ R = λ 1+ a 2 ) 4γ 2 τ 2σ 2R β Z τ R

32 Laser FEL a = λ R P ( λ R = λ 1+ a 2 ) 4γ 2 Z = 4πR 2 λ ρ = 1 2 γ 3 Iλ 4 P σ 4 e-beam σ = ε nβ γ L g = λ 4πρ ; I ; Δγ γ Δλ R λ R = ρ Conditions to operate a Thomson Source in FEL mode Laser length cτ =1L g Beam-laser overlap (laser uniform in x,y,z) R = 2σ cτ 2Z Laser ripples Δ Δa a Δλ R = 2a 2 λ R 1+ a Δ Δ ρ 1+ a 2 2 2a 2 Laser bandwidth Δλ R λ R = Δλ λ = cτ λ cτ λ ρ

33 Conditions to operate a Thomson Source in FEL mode FEL bandwidth broadening due to beam emittance Δλ R γ 2 θ 2 λ R 1+ a 4ε 2 n 2 σ 2 Δλ R λ R α 1 αρ ( λ R = λ 1+ a 2 + γ 2 θ 2 ) 4γ 2 ε n 1 2 αρ σ L g = λ 4πρ Z R = 4πσ 2 λ R ρ = Z R λ R λ L G 8π 2 2 σ Generalized Pellegrini criterion ε n α Z R L G λ R γ 2 2π

34 Generalized Pellegrini criterion ε n α Z R L G λ R γ 2 2π LCLS λ R 1 Angstrom FEL-Thomson γ = λ w = 2.5 cm L g Z R 1 m ε n < μm 4π ε n < γ = 3 λ =1 μm L g 1 μm ; Z R 1 m π.11 μm

35 Satisfying all conditions above implies: ε n = λ 5.62 U = 47λ Δ 2 γ =.68 λ R =12λ 3 3 I Δ 2 Δ 4 I 2 L G =.44λ /Δ ρ = λ 3 Δ 5 I P = Δ τ = λ Δ Z = 2.2λ Δ a =1.12 ρ =.18Δ σ =.21λ / Δ β =.18λ 3 I Δ 5

36 For the case of a Ti:Sa laser we derive: ε n =.14 μm U =.37 Δ 2 [J] P =.31 Δ [TW] γ =1.47 I Δ 2 λ R = 263Δ Δ 3 [Angstrom] I 2 3 τ =1.2 Δ [ps] L G = 35 /Δ [μm] ρ = 222Δ Δ2 Z =.18 Δ [mm] 3 I a =1.12 Δ [%] ; I [A] ρ = Δ σ =1.7/ Δ [μm] β =.3 Δ I 3 [mm] Δ 2

37 ε n =.14 μm U =1.5 J P = 3.1 TW a =1.12 Setting Δ =.5 % and I = 17 A Classical SASE γ = 28 λ R = 5.7 Angstrom τ = 2.4 ps ρ = σ = 2.4 μm L G = 7 μm ρ = 6 Z =.36 mm β =1.14 mm

38 ε n =.14 μm U = 37 J P =.6 TW a =1.12 Setting Δ =.1 % and I = 25 A Quantum FEL γ = 93 λ R =.52 Angstrom τ =12 ps ρ = σ = 5.4 μm L G = 35 μm ρ =.35 Z =1.8 mm β =18.8 mm

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40 up to photons per 6 kev, emitted in a coherent diffraction limited radiation beam, Δθ=3 μrad (cmp. 1 9 ph/pulse in Δθ=3 mrad of incoherent Thomson radiation)

41 Brilliance of X-ray radiation sources λ (nm) Compact Thomson Sources extend SR to hard X-ray range allowing Advanced Radiological Imaging inside Hospitals TTF SPARX Coherent Thomson Sources will push the achievable brilliance if laser pulses with ΔI/I < Δω/ω = will be made available THOMSON-FEL PLASMON-X

42 GeV-class IFEL design: Application of IFEL scheme as 4 th generation light source driver Compact-size accelerator ESASE benefits intrinsic Exponential gain length reduction Absolute timing synchronization with external laser Control of x-ray radiation pulse envelope Advanced Accelerator driven light source Design exercise aimed to extend the energy and wavelength reach of planned SPARC linac Initial e-beam energy (γ value) Initial e-beam intrinsic energy spread Initial e-beam current Laser wavelength Laser peak power Nominal length of wiggler, L w 21 MeV.1% (1σ) 1 ka 8 nm 2 TW 2 cm

43 IFEL design 2 2 Resonant energy (MeV) Distance along the undulator (m) Undulator period (cm) Magnetic field amplitude (kgauss) γ i φ i energy distribution Longitudinal phasespace zpos = 1.996m ICFA FLS-26 Phase distribution Workshop - DESY, May 18th 26 Final output parameters Energy 1.7 GeV Energy spread <.8 % Microbunch length 25 as Peak current > 6 kamp Avg. gradient 75 MeV/m

44 Conclusions Sending such a beam into an undulator FEL λ = 3 nm (water window). Peak power 1 GW in 3 attoseconds Among laser accelerators, the IFEL offers best control of the longitudinal phase space. Preserving ultrashort pulse structure in the radiation output requires some precautions in the design of the FEL amplifier (slippage problems) but can be done. Path towards ultrashort probe beams pass through fa synergy between laser and accelerator worlds. Peak Power (W) Current (A) Coordinate along the bunch (mkm) Coordinate along the bunch (mkm)

45 DZ_[mm] HSPACE.OUT Count 2 QuickTime and a TIFF (Uncompressed) decompressor are needed to see this picture Range

46 Best result in 24 σ x = 8.7µm (1nC Solenoid lens) Beam energy [MeV] z [m] Long. emit. [kev-mm] rms en.-spread [KeV] x-rms beam spot [mm] 2, 1,5 1,,5, z [m] 2, 1,5 1,,5, rms norm. transv. emitt. [mm-mrad] x-rms beam spot [mm],5,4,3,2,1 Zoom of the maximum focal spot, 12,28 12,3 12,32 12,34 z [m],5,4,3,2,1, rms norm. transv. emitt. [mm-mrad] Linear correlation correction, using the second TW acceleration structure: Ez=2.7 MV/m, Фi=85 Quadratic correlation correction, using a dedicated x-band structure : Ez=3 MV/m Фi=275 The results seem to be good especially for the very low longitudinal energy spread. Keeping in consideration that the beta in the focal spot is about 5 mm, the principal limitation is due to bunch length.

47 ,8,7,6,5,4,3,2,1, 12,24 12,26 12,28 z [m] x-rms beam spot [mm] rms norm. transv. emitt. [mm-mrad] 25 best result (2.5nC Solenoid lens) , 1,5 1,,5 x-rms beam spot [mm] Beam energy [MeV], z [m] Long.emit.[KeV-mm] rms en.-spread [KeV] z [m]

48 Triplet configuration for the final focus system Permanents magnets (1nC Bunch) A - case Triplet configuration: Ideal Q-length = 1.46 cm Q-Gradient = 3 T/m X - rms beam spot [mm],3,25,2,15,1,5, 12, 12,2 12,4 12,6 12,8 12, X rms norm. transv. emitt. [mm-mrad] σ-x =1 µm z [m] Y - rms beam spot [mm],3,25,2,15,1,5, 12, 12,2 12,4 12,6 12,8 12, Y rms norm. transv. emitt. [mm-mrad] σ-x =25 µm z [m]

49 Triplet configuration for the final focus system Permanents magnets (1nC Bunch) B - case Triplet configuration: Q1-length = 1. cm ; Q2-length = 2. cm ; Q3-length = 2. cm Gradient = +3 ; -3; +3 (T/m) Position, Q1 = m; Q2 = m; Q3 = m X - rms beam spot [mm],3,25,2,15,1,5, , 12,5 12,1 12,15 12,2 12,25 z [m] X rms norm. transv. emitt. [mm-mrad] σ-x = 1 µm Y - rms beam spot [mm],3,25,2,15,1,5, , 12,5 12,1 12,15 12,2 12,25 z [m] Y rms norm. transv. emitt. [mm-mrad] σ-x = 18 µm

50 Triplet configuration for the final focus system Permanents magnets (1nC Bunch) C - case Triplet configuration- thin lens: Ideal Q-length = 1. cm Q-Gradient = 645 T/m X - rms beam spot [mm],3,25,2,15,1,5, 12, 12,5 12,1 12,15 12,2 z [m] X rms norm. transv. emitt. [mm-mrad] σ-x = 1 µm Y - rms beam spot [mm],3,25,2,15,1,5, 12, 12,5 12,1 12,15 12,2 z [m] Y rms norm. transv. emitt. [mm-mrad] σ-x = 35 µm

51 σ γ /<γ>,55,5,45,4,35,3,25,2 Best result in 24 σx = 8.7µm (1nC Solenoid lens), %cut % charge 1 25 best results (1nC Solenoid lens) %cut σ x [mm],12,1,98,96,94,92,9,88,86,84, %cut ε nx [mm x mrad] 1,5 1,45 1,4 1,35 1,3 1,25 1,2 1,15 1,1 1,5 1,,95,9,85, %cut σ γ /<γ>,55,5,45,4,35,3,25,2, % cut % charge % cut σ x [mm],12,1,98,96,94,92,9,88,86, % cut ε nx [mm x mrad] 1,5 1,45 1,4 1,35 1,3 1,25 1,2 1,15 1,1 1,5 1,,95,9,85, % cut best results with triplet (1nC Solenoid lens) ONLY X PROIECTION σ γ /<γ>,55,5,45,4,35,3,25,2, % cut % charge % cut σ x [mm],12,1,98,96,94,92,9,88,86, % cut ε nx [mm x mrad] 1,5 1,45 1,4 1,35 1,3 1,25 1,2 1,15 1,1 1,5 1,,95,9,85, % cut

52 3-5 fs synchr. Ti:Sa 2-TW Laser System 2 mj, 1 ps flat top 2 nc, 1 ps 1 J, 1 ps gaussian Compr. 1 J, 1 fs gaussian ε n =2 μm, σ =5 μm, Δγ/γ= μj 2 pc, 1-6 fs ε n =.2 μm, σ =1 μm Two additional beam lines at SPARC for plasma acceleration and monochromatic X-ray beams 1 nc, 1 ps, ε n =1 μm

53 A 3D Model View of the buildings from outside CANVAS TENT STORAGE AREA CONTROL ROOM ACCELERATOR UNDERGROUND BUNKER MODULATOR & KLYSTRON HALL ACCESS TO UNDERGROUND BUNKER

54 Pumps Seed Line Verdi Nd:YVO 4 Mira Ti:Sa Oscillator 8 nm 1 nj 8 MHz 1 fs Evolution Nd:YLF Continuum Nd:Yag Hidra CPA Ti:Sa Amplifier RGA + 2 MP LASER SYSTEM Custom-laser purch. from Coherent Flat Top Time Profile rise time < 1 ps THG UV Stretcher DAZZLER TeO 2 8 nm 5 mj 1 Hz 1 fs 266 nm 4 mj 1 Hz 1 fs 266 nm 1,8 mj 1 Hz.5-12 ps Ext. Synch. Synchro Lock PLL f/36 Pulse Shaping developed in house RF-laser jitter <.5 ps RF Reference R&S 2,856 GHz long term goal: 1 fs

55 Schedule of the planned PLASMONX activity Activit y/y ea r Set up c lu ste r f or par a llel co mpu ting Tes t exp erim ent CEA -Sa cl a y D evelo p m e nt o f m.w. PI C co d es Mod elling o f a ccel er a tio n sche m es Mod elling o f T.S. D esig n of L a ser Sy stem Set up L ASE R L AB O R ATOR Y a t LNF Set up P ha se 1 : 3 fs,.1 TW M Set up I II am p lifica tio n sta g e D evelo p m e nt o f t he O PCP A am p lifier s In sta lla tio n of las er dia g no stics Pha se 2 : 1 TW com pr ess io n te st M 2.5 Meuro bid is ongoing for the FLAME laser IV am p lifica tio n sta g e Pha se 3 : 1 T W c o m p res sion test M Self inje ctio n LW F A exp erim ent s Ex te rn a l i n jec tio n L WF A te st M Set up ad d ition a l b ea m -lin e a t L NF Set up la ser b e am tra n sp o rt to LI N AC Se t up laser be am electron bu nch inte raction Sy nc hroniz a tio n R &D a nd setup Th om so n so ur ce te st M TS b ea m us ers (MA MB O, etc ) QFEL experim. under study with PLASMONX facility

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