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Physics Challenges of High-Intensity X-ray and Muon Beams in Nuclear Photonics

Explore the technological challenges and opportunities in producing high-intensity X-ray and muon beams for nuclear photonics applications. Learn about the physics requirements, such as spectral densities and peak brilliance, for advancing nuclear physics and colliders. Discover the potential of Compton sources in generating electron-photon colliders and achieving maximum luminosity. Dive into the details of gamma beam systems and photon-photon scattering for cutting-edge research in nuclear photonics and muon beams.

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Physics Challenges of High-Intensity X-ray and Muon Beams in Nuclear Photonics

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  1. Challenges and Opportunities of high intensity X/g photonbeams for Nuclear Photonics and Muon Beams Luca Serafini – INFN-Milan, EuroGammaS scientific coordinator V. Petrillo, C. Curatolo – Univ. of Milan • Physics/Technology Challenges of electron-(optical)photon colliders as X/g beam Sources using Compton back-scattering • Need of high peak brightness/high average current electron beams (cmp. FEL’s drivers) fsec-class synchronized and mm-mrad-scale aligned to high peak/average power laser beams • Main goal for Nuclear Physics and Nuclear Photonics: Spectral Densities > 104Nph/(s.eV) (state of the art: HigS 300, bremsstrahlung sources 1) photon energy range 1-20 MeV, bandwidths 10-3 class

  2. Main goal for MeV-class g - g and TeVg - nucleon colliders: Peak Brilliance > 1021Nph/(s.mm2.mrad2.0.1%)109<Nph<1013 Source spot size mm-scale (low diffraction, few mrad) Tunability, Mono-chromaticity, Polarization (H,V,C) • ELI-NP-GammaBeamSystem in construction by EuroGammaS as an example of new generation Compton Source • Photon-Photon scattering (+ Breit-Wheeler: pair creation in vacuum) is becoming feasible with this new generation g-beams • Interesting new option for low emittance pion and muon beams generation using X-FEL’s and LHC beams (demonstrator based on Compton Source and SPS beams)

  3. If the Physics of Compton/Thomson back-scattering is well known…. the Challenge of making a Compton Source running as an electron-photon Collider with maximum Luminosity, to achieve the requested Spectral Density, Brilliance, narrow Bandwidth of the generated X/g ray beam, is a completely different issue/business ! Courtesy L. Palumbo

  4. Compton Inverse Scattering Physics is clear: recall some basics 3 regimes: a) Elastic, Thomson b) Quasi-Elastic, Compton with Thomson cross-section c) Inelastic, Compton, recoil dominated Courtesy V. Petrillo

  5. g-g Colliders Polarized Positrons X/g [MeV] FELs (pureg2) Nuclear Photonics D Thomson X-rays 1 GeV 1 TeV Te [MeV]

  6. We need to build a very high luminosity collider, that needs to maximize the Spectral Luminosity, i.e. Luminosity per unit bandwidth negligible diffraction 0 crossing angle • Scattered flux • Luminosity as in HEP collisions • Many photons, electrons • Focus tightly • ELI-NP f electrons laser • cfr. LHC 1034, Hi-Lumi LHC 1035

  7. 300 mrad 60 mrad Courtesy M. Gambaccini

  8. Bandwidth due to collection angle, laser and electron beam phase space distribution electron beam laser

  9. ELI-NP γ beam: the quest for narrow bandwidths (from 10-2 down to 10-3) Courtesy V. Zamfir – ELI-NP

  10. Spectr. Density = 1 Spectr. Density > 103

  11. courtesy of G. Travish (UCLA)

  12. ELI-NP GBS (Extreme Light Infrastrucutre Gamma Beam System) Main Parameters outstanding electron beam @ 750 MeV with high phase space density (all values are projected, not slice! cmp. FEL’s) Back-scattering a high quality J-class ps laser pulse not sustainable by RF, Laser!

  13. Accelerator and Equipments in ELI-NP Building

  14. 109 Authors, 327 pages published today on ArXiv http://arxiv.org/abs/1407.3669

  15. Electron beam is transparent to the laser (only 109 photons are back-scattered at each collision out of the 1018 carried by the laser pulse) Optical system: laser beam circulator (LBC)for J-class psec laser pulses focused down to mm spot sizes Circulator principle PARAMETERS = OPTIMIZED ON THE GAMMA-RAY FLUX Laser power = state of the art Angle of incidence (φ = 7.54°) Waist size (ω0 = 28.3μm) Number of passes = 32 passes • 2 high-grade quality parabolic mirrors • Aberration free • Mirror-pair system (MPS) per pass • Synchronization • Optical plan switching • Constant incident angle = small bandwidth 30 cm 2.4 m courtesy K. Cassou

  16. ELI-NP-GBS High Order mode Damped RF structure Unlike FEL’s Linacs, ELI-NP-GBS is a multi-bunch accelerator, therefore we need to control the Beam-Break-Up Instability to avoid complete deterioration of the electron beam emittance, i.e. of its brightness and phase space density courtesy David Alesini

  17. C-BAND STRUCTURES: HIGH POWER TEST SETUP The structure has been tested at high power at the Bonn University under RI responsibility. Successfully tested at full power (40 MW) courtesy David Alesini

  18. Brilliance of Lasers and X-ray sources Thomson/Compton Sources ELI 12.4 1.24 0.124 l (nm) BELLA FLASH Outstanding X/g photon beams for Exotic Colliders

  19. A MeV-class Photon-Photon Scattering Machine based ontwin Photo-Injectors and Compton Sources • g-ray beams similar to those generated by Compton Sources for Nuclear Physics/Photonics • issue with photon beam diffraction at low energy! • Best option: twin system of high gradient X-band 200 MeV photo-injectors with J-class ps lasers (ELI-NP-GBS)

  20. peak cross-section, ≈1.6 µbarn at Tunability! Narrow bdw! cross-section for unpolarized initial state (average over initial polarizations) optical transparency of the Universe courtesy E. Milotti

  21. courtesy E. Milotti

  22. threshold of the Bethe-Heitler process threshold of the Breit-Wheeler process integrated luminosity corresponding to a bare minimum of about 100 scattering events (total). 1 nb-1 ECM ≈ 880 keV ECM ≈ 13 MeV 10 pb-1 ECM ≈ 630 keV ECM ≈ 140 MeV courtesy E. Milotti

  23. We evaluated the event production rate of several schemes for photon-photon scattering, based on ultra-intense lasers, bremsstralhung machines, Nuclear Photonics gamma-ray machines, etc, in all possible combinations: collision of 0.5 MeV photon beams is the only viable solution to achieve 1 nbarn-1 in a reasonable measurement time. • Colliding 2 ELI-NP 10 PW lasers under construction (ready in 2018), hn=1.2 eV, f=1/60 Hz, we achieve (Ecm=3 eV): LSC=6.1045, cross section= 6.10-64, events/sec=10-19 • Colliding 1 ELI-NP 10 PW laser with the 20 MeV gamma-ray beam of ELI-NP-GBS we achieve (Ecm=5.5 keV): LSC=6.1033, cross section=10-41, events/sec = 10-8

  24. Colliding a high power Bremsstralhung 50 keV X-ray beam (unpolarized, 100 kW on a mm spot size) with ELI-NP-GBS 20 MeV gamma-ray beam (Ecm=2 MeV) we achieve: LSC=6.1022, cross section=1 mbarn, events/s = 10-8 4) Colliding 2 gamma-ray 0.5 MeV beams, carrying 109 photons per pulse at 100 Hz rep rate, with focal spot size at the collision point of about 2 mm, we achieve: LSC=2.1026, cross section = 1 mbarn, events/s=2.10-4, events/day=18, 1 nanobarn-1 accumulated after 3 months of machine running.

  25. Luminosities of Colliders involving Photon Beams at various c.m. energy • Compton Sources: L=1035 cm-2s-1at 1-100 keV c.m. energy (ELI-NP-GBS like) • g-g colliders for photon-photon scattering experiment and Breit-Wheeler: L=1026cm-2s-1at 0.5-2 MeV c.m. energy • Photon–photon collider with 2x10 PW ELI Laser (most powerful of this decade): L=1045 cm-2s-1at 3 eV c.m. energy • LHC proton (7 TeV) – XFEL photon (20 keV) collider : ultimate Luminosity (1012 p 100ns, TW-FEL* as for LCLS-II SC-CW) L=1038 cm-2s-1at 1.2 GeV c.m. energy *C.Pellegrini et al., PRSTAB 15, 050704 (2012) production of low emittance p/m/n/ beams… Is it of any interest?

  26. Not a new idea.. but A.Dadi and C.Muller analyzed a multi-photon reaction and didn’t make evaluations of the phase spaces for the generated pion/muon beams

  27. 2 Ingredients to make a Collider Source of a low emittance (high phase space density, high brilliance) secondary beam • Large Lorentz boost to collimate within narrow solid angle (in the Lab frame) all reaction products, i.e.gcm >> 1 • Energy available in c.m. frame as momentum of secondary particles much smaller than their invariant mass energy Emittance of secondary beam generated in collision: combination of emittance of momentum-dominant beam (protons for LHC-FEL, electrons for Compton Sources) and transverse momentum in c.m. frame (-> transverse momentum is invariant to Lorentz boost, i.e. transverse temperature/emittance is also invariant to Lorentz boost)

  28. hn 20 keV FEL photon is seen as a 2. gp. hn = 300 MeV by the proton in its rest frame (max total cross section of pion photo-production 0.25 mbarn)

  29. Momentum in laboratory frame: nF nB pF pB Large Lorentz boost : gcm = 5830

  30. Phase Space Distribution Results of a montecarlo event generator with (upper) and without (lower) LHC proton beam emittance (proton rms transv. momentum 200 MeV, sx’ = 20 mrad) 2.5 TeV/c tm+ 50 ms 2.5 TeV/c tp+ 0.5 ms 150 GeV/c tm+ 5 ms 260 GeV/c tp+ 48 ms 20 mrad

  31. Populating the Phase Space: combination of p-beam transverse emittance (temperature) and stochastic transverse temperature increase due to decay sequence (p, hn) -> (p+, n) -> (m,n) n stop-band at q=20 mrad (200 MeV p transv. mom.)

  32. outstanding pion beam emittance < 10 mm.mrad thanks to 7 mm emitting source spot-size and low p+ rms trans. momentum (150 MeV: ppx /mp=1)

  33. Luminosity issues and pion/muon/neutron/neutrinos fluxes a) Assuming LHC p-beam at 1012 intensity and 10 MHz rep rate vs. 1013 photons/pulse SC-CW XFEL (run in long 200 fs pulse and tapering), focused down to 7 mm rms spot size, we can get 6.104 pions per bunch crossing (no collective beam-beam at IP w.r.t. p-p collisions) b) We have a pion photo-cathode: how to match the pion beam into a storage ring / transport line is an open problem… c) Assuming the low p-beam emittance can be preserved, we can accumulate muons over half ot their life-time (10-60 ms), reaching Nm=3.109 , which is enough, at 10 MHz rep rate, to reach a muon collider luminosity of about 1031cm-2s-1, without need of cooling nor acceleration.

  34. d) Life-time of p-beam is about 10 hours (taking into account also p0, e+/e- and Compton events) e) p- production requires deuteron beams (simultaneous production of p+ and p- thanks to pion-photoproduction quasi-symmetric cross section on deuteron) f) Potentials for highly collimated neutrino and neutron beams in the 10 GeV – 1 TeV range Is it going to be an interesting alternative option for m-collider? Using FCC beams we would need 3 keV X-rays -> simpler and cheaper FEL (5-6 GeV Linac vs. 15-18 GeV Linac for 20 keV photons and larger number of photons)

  35. A Compact (10 m, 10 M€) Demonstrator at SPS of a Pion Photo-cathode Compton Source: 109 hn/pulse @ 350 keV vs. 400 GeV protons -> measure diff. cross. sect., phase space accumulation (1 p / b. cross.)

  36. Thank you for your kind attention Special Thanks to: C. Meroni, A. Ghigo, D. Palmer on the pion beams. E. Milotti, C. Curceanu for material on the photon-photon scattering. D. Alesini, N. Bliss, F. Zomer, K. Cassou, A. Variola and the whole EuroGammaS collaboration on the ELI-NP-GBS Project.

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