Prospettive ed Esperimenti Futuri a LIFE (il punto di vista della fisica dei fasci) Luca Serafini, INFN-Milano FE = Fasci Estremi (Laboratorio Interdisciplinare con Fasci Estremi?) Estremi in Phase Space Density (Brightness, Brilliance) Estremi in Rapidity (peak flux, Np/Dt2 ) Estremi in Coherence and Duration (fs to attos X-ray pulses) Estremi in Complexity and Multiplicity: synchronous (e-,X,hv), (p,X), (g,e+) (n,g,X,hv) Estremi in Coupling e-/rad. (FEL, IFEL, AOFEL,Channeling) I Workshop LIFE, LNF, 20-02-2009

Brightness and Brilliance Figures of Merit Brightness and Brilliance I Workshop LIFE, LNF, 20-02-2009

The Brightness Chart [A/(m.rad)2] AOFEL n [m] 1013 1014 1015 1016 1017 I [kA] 1018 Self-Inj1 SPARX Photo-injectors SPARC Ext-Inj2 SPARX 1 pC The Brightness Chart [A/(m.rad)2] 1- see C. Benedetti’s talk 2 – see P. Tomassini’s talk I Workshop LIFE, LNF, 20-02-2009

The 6D Brilliance Chart [A/((m.rad)20.1%)] Dg/g [0.1%] 1014 1015 1016 1017 Bn AOFEL SPARX 1 pC SPARX Self-Inj Ext-Inj SPARC The 6D Brilliance Chart [A/((m.rad)20.1%)] I Workshop LIFE, LNF, 20-02-2009

Rapidity I Workshop LIFE, LNF, 20-02-2009

Physical Principles of the Plasma Wakefield Accelerator Courtesy of T. Katsouleas Plasma acceleration experiments with SPARC/X e- beams Space charge of drive beam displaces plasma electrons - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + + + - - - + - - - - - + + - - + + + + + - - - + + + + + + + - + + + + - - - + + + - + + + + + + + + + - - + + + + + + + + + + + - - - - - - - - - - - - electron beam - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Ez Plasma ions exert restoring force => Space charge oscillations Wake Phase Velocity = Beam Velocity (like wake on a boat) Wake amplitude Transformer ratio I Workshop LIFE, LNF, 20-02-2009

I Workshop LIFE, LNF, 20-02-2009

Scattered photons in collision Thomson X-section Scattered flux Luminosity as in HEP collisions Many photons, electrons Focus tightly Short laser pulse; <few psec (depth of focus) I Workshop LIFE, LNF, 20-02-2009

Rapidity I Workshop LIFE, LNF, 20-02-2009

Coherence and Time Duration I Workshop LIFE, LNF, 20-02-2009

AOFEL CO2 envelope CO2 focus TiSa envelope e- beam plasma r m] TiSa envelope TiSa pulse e- beam plasma Lsat=10LG=1.3 mm (=0.002) Z [m] I Workshop LIFE, LNF, 20-02-2009

Longitudinal phase space and density profile Selection of best part in the bunch: 40 pC in 2 fs (600 nm) projected rms n = 0.7 m <> <>  I Workshop LIFE, LNF, 20-02-2009

GENESIS Simulations starting from actual phase space from VORPAL (with oversampling) =2.5 m (CO2 laser focus closer to plasma) Simulation with real bunch After 1 mm : 0.2 GW in 200 attoseconds Lbeff < 2 Lc I Workshop LIFE, LNF, 20-02-2009

GENESIS Simulations for laser undulator at 1 m to radiate at 1 Angstrom Peak power 100 MW in 100 attoseconds Average power (Lsat~500 m, Psat~10 MW) Coherence Time duration Simulation with real bunch =3.5 m Field I Workshop LIFE, LNF, 20-02-2009

I Workshop LIFE, LNF, 20-02-2009

Slice 8, I=25 kA Equivalent Cathode I Workshop LIFE, LNF, 20-02-2009

Multeplicity and Complexity I Workshop LIFE, LNF, 20-02-2009

Two ways to get pol. e+ (1) Helical Undurator (2) Laser Compton courtesy of T. Omori (KEK) e- beam E >150 GeV Undulator L > 200 m Our Proposal (2) Laser Compton I Workshop LIFE, LNF, 20-02-2009

I Workshop LIFE, LNF, 20-02-2009

An electron beam energy up to 1 An electron beam energy up to 1.5 Gev would allow the production of polarized photons at 50 MeV, which seems the optimized photon energy for efficient production of polarized photons I Workshop LIFE, LNF, 20-02-2009

Preliminary calculations show that up to 1010 polarized photons per pulse should be expected using about 1.0 J of infrared radiation and a 1 nC beam focused to spotsizes of 5 microns. Including the capture efficiency, we can estimate up to few per cent (2 %) of these photons to yield a usable polarized positron. I Workshop LIFE, LNF, 20-02-2009

With a smaller electron energy (< 300 MeV), like in the case of the upgraded SPARC energy, the energy of ICS photons is smaller (about 2-4 MeV photons ), still useful for e+ polarization tests. I Workshop LIFE, LNF, 20-02-2009

Gamma on D2O Photo-neutron Source Gamma from the “LIFE” Thomson backscattering source Target of heavy water D2O (cost about 400€/l) Target dimension (used in simulations) F=2cm - 1 mm ; length 10, 25, 50 cm (target filling cost :12-60 € for F=2cm) Take advantage of high peak flux of monochromatic g beams from tunable, mm spot size, ps pulse Thomson Source I Workshop LIFE, LNF, 20-02-2009

Neutron Produced: F. Broggi, FLUKA2 Photon beam Photon beam diameter = 1 mm FWHM Photon fluence Simulation performed with 10 different runs of 106 primary photons I Workshop LIFE, LNF, 20-02-2009

Neutron produced vs photon energy/target length (Target diameter 2 cm) Optimum g energy about 5 MeV The forward production decreases with the target length (self-absorption): The backward production is constant The side production increases with the target length. I Workshop LIFE, LNF, 20-02-2009

Neutron Spectra (5 MeV gamma on 25 cm D2O) (target diameter 2 cm) The maximum n energy is about by arranging the photon energy different neutron energy will be available. I Workshop LIFE, LNF, 20-02-2009

Target diameter 1 mm I Workshop LIFE, LNF, 20-02-2009

Small-Big Target Small Target Large Target Neutron/g Error % Forward Side 2.69E-03 8.53E-02 2.65E-03 2.89E-03 Back 2.82E-06 2.63E+00 6.76E-05 3.90E+00 I Workshop LIFE, LNF, 20-02-2009

Coupling I Workshop LIFE, LNF, 20-02-2009

IFEL acceleration (P. Musumeci) Inverse Free Electron Laser accelerator is a proven and reliable technique to accelerate with very high gradient high quality electron beams. (successful experiments @ UCLA and BNL) It is not well suited for HEP applications, but renovated interested in the US as light sources driver application (UCLA-LLNL funded proposal). Two steps: An undulator to demonstrate 200 MeV/m energy gradient is already available @ UCLA. Need 3-4 TW 100 fs laser beam. For 1.7 GeV module need 20 TW 100 fs laser beam + helical undulator. I Workshop LIFE, LNF, 20-02-2009

IFEL acceleration@SPARC Sending the IFEL beam into an undulator FEL radiation @ l = 3 nm (water window) Slippage dominated regime. Start-to-end --TREDI into GENESIS-- simulations (see Musumeci, FEL talk Berlin 2006) With full FLAME power, final energy after 2 m optimized helical undulator could increased to > 2.1 GeV. Simulated longitudinal phase space output I Workshop LIFE, LNF, 20-02-2009

@ Channeling of Charged Particles @ Amorphous: @ Channeling: Atomic crystal plane planar channeling e + e- Atomic crystal row (axis) axial channeling e- the Lindhard angle is the critical angle for the channeling

Channeling of Charged Particles & Channeling Radiation @ Channeling: Atomic plane of crystal e + - the Lindhard angle is the critical angle for the channeling @ Channeling Radiation: CUP project studies the positron channeling for the development of Crystal Undulator for Positrons and represents the first step of an ambitious project that investigates the possibility to create new, powerful sources of high-frequency monochromatic electromagnetic radiation: crystalline undulator and -laser, based on crystalline undulator. The physical phenomena to investigate are essentially two: the spontaneous undulator radiation by channeling of relativistic positrons and the stimulated emission in periodically bent crystals (the lasing effect). - optical frequency Doppler effect - Powerful radiation source of X-rays and -rays: polarized Tunable (keV - MeV) narrow forwarded

Channeling Radiation - @ Channeling Radiation: - optical frequency Doppler effect - Powerful radiation source of X-rays and -rays: polarized tunable narrow forwarded

Channeling Radiation & Thomson Scattering - radiation frequency - - number of photons per unit of time - - radiation power - @ comparison factor: Laser beam size & mutual orientation @ strength parameters – crystal & field:

Channeling Radiation & Thomson Scattering For X-ray frequencies: 100 MeV electrons channeled in 105 mm Si (110) emit ~ 10-3 ph/e- corresponding to a Photon Flux ~ 108 ph/sec ChR – effective source of photons in very wide frequency range: in x-ray range – higher than B, CB, and TS however, TS provides a higher degree of monochromatization and TS is not undergone incoherent background, which always takes place at ChR

Conclusions Self-Inj : neutron source, aferburner (relativistic piston) Ext-Inj: polarized positrons (test, compact GeV, good brightness) AOFEL: table top X-FEL (max brightness, step density gas jet) 10 MeV’s g beams: nuclear physics (Giant Resonances) Photoinjector beams still playing relevant role in years to come (FEL, IFEL, Channeling, THz, TS, etc.) I Workshop LIFE, LNF, 20-02-2009

I Workshop LIFE, LNF, 20-02-2009

@ Channeling: Continuum model screening function of Thomas-Fermi type screening length Molier’s potential Lindhard potential …… Firsov, Doyle-Turner, etc. Lindhard: Continuum model – continuum atomic plane/axis potential

@ Bremsstrahlung & Coherent Bremsstrahlung vs Channeling Radiation @ amorphous - electron: Radiation as sum of independent impacts with atoms Effective radius of interaction – aTF Coherent radiation length lcoh>>aTF Deviations in trajectory less than effective radiation angles: Nph Quantum energy

@ Bremsstrahlung & Coherent Bremsstrahlung vs Channeling Radiation @ interference of consequent radiation events: phase of radiation wave Radiation field as interference of radiated waves: Coherent radiation length can be rather large even for short wavelength @ crystal: d Nph Quantum energy

@ Bremsstrahlung & Coherent Bremsstrahlung vs Channeling Radiation @ crystal: d channeling at definite conditions channeling radiation can be significantly powerful than bremsstrahlung B: CB: ChR: