Advanced Accelerator Concepts SPARX how the FEL can

Advanced Accelerator Concepts @ SPARX (how the FEL can push the high energy frontier) Luca Serafini - INFN/MI • FELs and High Energy Frontier Accelerators: what do they have in common? High phase space density beams • FELs and Plasma Accelerators: can they cross-fertilize each other to push their limits? Yes, through exploitation of ultra-short electron bunches (fsec, attosec-class) eventually modulated in COMB beams • Do they have Common Goals? Space/time resolutions below [ fsec / Angstrom] , Collective Fields above [ TV/m ] Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Historical schematic of accelerators: Particle physics leads, spin-offs follow quickly Betatron FFAG, etc. Synchrotron Medicine Cyclotron 1930 Ion Linear Accelerators Electrostatic Accelerators Circular Collider Superconducting Circular Collider Light sources (3 rd Generation) VLHC? Muon Collider? X-ray FEL Electron Linear Accelerators Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010 2030 Nuclear physics Electron Linear Colliders Ultra-High Energy LC? Laser/Plasma Accelerators?

The energy challenge Avoid gigantism Cost above all Higher fields give physics challenges Circular machines: magnets Linear machines: high field acceleration Enter new world of high energy density physics Beam density, energy High energy density in action at the LHC Beam quality must increase to compensate smaller cross-section Stored field energy XCVI Congresso Naz. SIF - Bologna -

The Luminosity Challenge Circular colliders provide high repetition rate Linear colliders have much lower repetition rate Use large N, small ; very large collective beam fields Inherent scaling for higher energy not enough: Must have very small phase space, focus well… Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Plasma Wakefield Acceleration (PWFA) Electron beam shock-excites plasma Same scaling as Cerenkov wakes, maximum field scales in strength as In “blowout” regime, plasma e-’s expelled by beam. Ion focusing + EM acceleration= plasma linac Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Ultra-high gradient PWFA: E 164 experiment at SLAC FFTB Uses ultra-short beam (20 m) Beam field ionization creates dense plasma Over 4 Ge. V(!) energy gain over 10 cm: 40 GV/m fields Self-injection of plasma e- s X-rays from betatron oscillations New experiments: >10 Ge. V in 30 cm plasma (E 167) Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010 Modified PRL cover ne=2. 5 x 10 17 cm-3 plasma M. Hogan, et al.

The Quest for ultra-short ultra-dense bunches Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Ultra-short beam application: IR wavelength PWFA Beam denser than plasma Very nonlinear plasma dynamics Pure ion column focusing for e-s Linac-style EM acceleration General measure of nonlinearity: R (mm) Ultra-high brightness, fs beams impact HEP also! Use 20 p. C LCLS beam in high n plasma In “blowout” regime: total rarefaction of plasma e-s Z (mm) MAGIC simulation of blowout PWFA case Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Optimized excitation With 2 fs LCLS beam we should choose For 20 p. C beam, we have 1 TV/m fields (!) Also w/o plasma (ionization) New frontier in atomic physics Collaboration formed OOPIC simulation of LCLS case UCLA-SLAC-USC Technical issues address 1 TV/m accelerating field: a dream for a table-top Te. V-class e-e+ collider? Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

How Short and How Bright can we go with SPARX? Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

1018 17 AOFEL 10 I [k. A] Self-Inj 1016 u g nchin city b o l e v r na Lami Ext-Inj S LCL SPARX 1015 1014 X-ray FEL @ 1 p. C c n l velo a m r o nch ity bu SPARC ing 1013 n [ m] The Electron Beam Brightness Chart [A/(m. rad)2] Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

We discovered a new regime of velocity bunching in which the beam is not only transversally laminar (as in photo-injectors running on the invariant envelope/Ferrario working point) but also longitudinally laminar (no cross-over among slices) We call this new regime Laminar Velocity Bunching Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Conventional Velocity Bunching Long. Emittance Dominated Longitudinal Focus with trajectory cross-over Laminar Velocity Bunching Space Charge Dominated Longitudinal Waist! Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Thanks to A. Bacci’s Gen. Alg. optimization we discovered that a FEL Linac can be run without any magnetic compression (nor quads, laminar flow through the end) as predicted long time ago by velocity bunching theory Extension of Ferrario’s working point up to final energy (750 Me. V)

Slice analysis with 0. 5 RF deg jitter (3 k. A in 150 fs spike) Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

It can drive a 20 nm SASE-FEL @ SPARX ! up to 1. 2 m. J per shot (6 GW) V. Petrillo (Genesys) Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Slice analysis for a 15 p. C bunch (1 k. A in 1. 2 fs spike) Focused down to 0. 1 mm it can drive a 6. 1019 cm-3 plasma with TV/m-class fields Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

How Plasma Accelerators can feedback on FELs improving their performances? Example: a Plasma Booster based on External Injection Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Layout SPARC hall Optical transfer line 0. 3 PW LASER PHOTOINJ LASER SEEDING LASER PLASMON. X EXT. INJ. THOMSON HHG DGL PHOTOINJECTOR UNDULATOR Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

External Injection Experiment • Injected Bunch: 13 p. C, 150 Me. V, 0. 6 mm. mrad, 3. 0 m rms spot, 2. 4 m rms length [circa 1 KA] • Laser: 7 J in 35 fs, w 0=32. 5 m, w 0_inj=135 m, guided over 30 ZR. • Plasma: Density profile increasing between 0. 6. 1017 cm-3 and 0. 8. 1017 cm-3 , “tapered channel” to guide the laser pulse. Acceleration Length circa 15 cm. • Numerica: Mobile Window at v=c, sampling at 46 mesh points / lp and 26 m. p. /w. Bunch sampled by 40000 particles Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Simulazione 2 Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Adiabatic Matching into Plasma Channel

Output Beam <E> = 2. 01 Ge. V DE/E = 0. 8% rms en=0. 6 m P. Tomassini (QFluyd 2) Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Brightness good enough to drive a X-ray FEL B_peak=2 I/e 2=3. 5. 1016 A/m 2 If this experiment confirms expectations (first injection tests expected in 2013) SPARX can be upgraded with a Plasma Booster (750 Me. V --> 1. 5 Ge. V in 10 cm plasma channel) Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Towards Me. V-class Compton Source at SPARX Option A): with SPARX energy 650 Me. V, collide with 2 nd -harmonic of FLAME (psec pulses) => narrow bandwidth (1%) lower flux (1010 ph/s, 1012 ph/s with recirculator ) Option B): with SPARX energy 900 Me. V, collide with IR FLAME pulses => larger bandwidth, larger flux (1011 ph/s, 1013 ph/s with recirculator ) Aiming at record spectral density of 104 ph/e. V/sec best of brehmstrahlung sources is 1 ph/e. V/sec Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Nph = 1. 3 1010 sec-1 Bandwith-rms = 25% 12 Me. V 16 Me. V 5 103 ph. e. V-1 sec-1 20 Me. V V. Petrillo Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Prospettive Future con gli Accel. a LNF, 11 -06 -2010

Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Fast monochromatic Positron beam production with Compton Source W Target 4 mm 70 cm Eg = 4, 10, 20 Me. V, Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010 Beam spot (1 mm) 1 -2 -5 mm

10 different FLUKA runs with 107 particle each 1 mm 2 mm 5 mm Target length

Spectra (double differential) 2 mm 1 mm 5 mm F. Broggi (Fluka) Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Target Geometry (mm) Positron produced (e+ pr-1) ± err% Length Radius Forward Side Backward 1 2 6. 9 E-02 ± 6 5. 4 E-04 ± 0. 6 2. 5 E-03 ± 0. 3 2 2 9. 2 E-02 ± 4 5. 7 E-04 ± 0. 1 3. 1 E-03 ± 0. 3 5 2 7. 6 E-02 ± 5 === 3. 2 E-03 ± 0. 3 Having a primary photon flux of 1010 photons/shot, about 6*108 forward positrons can be obtained, with 10 ps long bunches (single shot) at 10% energy spread, allowing studying the spectroscopy of Para-Positronium (half life 100 psec) (priv. comm. M. Giammarchi INFNMi and G. Consolati Poli-Mi). Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

CONCLUSIONS • Electron beams for advanced FELs have similar demands than those for the High Energy Frontier Accelerators • Brightness, rapidity, ultra-high density • What does it take to design and develop a Frontier Machine? exploit Synergy and Integration both in Instrumentation and in People Expertise • Last but not least: ongoing brain-storming on ideas for an electron-photon collider at 2*Sqrt[g (10 Me. V)*e-(700 Me. V)]= 170 Me. V in the c. m, enough to drive e- g -> p 0 e- with 1028 -1030 luminosity (search for light bosons)

Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Past the breakdown limit: Plasma Accelerators Very high energy density laser or e- beam excites plasma waves as it propagates Schematic of laser wakefield Accelerator (LWFA) Extremely high fields possible: Ex: tenous gas density XCVI Congresso Naz. SIF - Bologna -

LI 2 FE: the Scientific Program The combined availability of these Beam Sources and related instrumentation, together with advanced expertise in the accelerator/laser/plasma physics and technologies, will lead to unprecedented potentials of research and discoveries at INFNLNF (multi-institutional effort, INFN, ENEA, CNR, many Univ. ) User experiments: application oriented (investigation of matter at functional level) Developer experiments: technique oriented (toward the high energy frontier, propedeutical to investigation of matter at fundamental level) Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

LI 2 FE Window of Opportunity (5 year span) Unprecedented results in Application Experiments due to unique beams available Crucial Role in advancing new technologies for the High Energy Frontier needless to say… we need the correct Spirit of sharing Expertise and Instrumentation Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010

Joint LI 2 FE/SPARX Meeting, INFN-LNF, 09/12/2010