BIG A Gamma Ray Source at FACET-II

Transcription

1 BIG A Gamma Ray Source at FACET-II Laser-Driven Radiation Sources for Nuclear Applications, GWU, December 13-15, 2015 Carsten Hast SLAC

2 Outline FACET-II in a Nutshell BIG: Beams of Intense Gamma-Rays at FACET-II BIG Parameter Summary SLAC FACET-II Science Workshop October 2015 Selected Physics Ideas Location of a Compton Source in FACET-II User Area Summary 2

3 FACET-II Uses the Middle 1/3 of the SLAC Linac State of the art S-Band Photo Injector 10 GeV electron and positron beams High charge, small spot sizes, high current 2-5nC, as small as 10/10/10 µm 3, >100kA 30Hz repetition rate (120Hz as an upgrade) Existing Ti/Saphire Laser System at User Area National User Facility Users will drive the experimental program 3

4 FACET II: High Gradient Acceleration High Brightness Beams Novel Radiation Techniques Trojan Horse Technique Compact high gradient plasma accelerator Plasma bubble act as ultra-highbrightness electron source with ε=~10-9 π mm mrad laser photons ~1m ~100µm electrons high energyγ s Polarized gamma beams 2 MeV - 4 GeV with high flux γ/sec for diverse research programs 4

5 BIG: Beams of Intense Gamma-Rays at FACET-II Gamma beams at FACET-II with Compton back scattering of 10µm, 800nm and 400nm laser beams Energy range: 2 MeV - 4 GeV Flux: γ/sec Nearly 100% polarization Modes of operations High peak flux single burst per pulse High duty factor trains of ~ 1,000 bunches/pulse White (un-collimated) gamma-rays mono-energetic (collimated) gamma-rays Linear, circular, elliptical polarization High-energy beam plus powerful laser systems deliver unprecedented combination of gamma-ray energy and flux 5

6 FACET-II Parameter Summary for BIG Lepton Beams Energy [GeV] ε NX x ε NY [µm x µm] σ X x σ Y [µm x µm] σ Z x ΔE/E [µm x %] 5nC e x 5 10 x x 0.3 2nC e x 3 20 x x 0.5 Lasers Energy / Power [ Joule / TW ] Rep rate [Hz] TI: Sapphire 1 / (120) τ [fs] λ [µm] CO 2 laser (upgrade) 0.1 / Gamma Beams (Inverse Compton) Energy [GeV] Intensity [#γ/pulse] Rep rate [Hz] TI: Sapphire 1.8 GeV (120*) CO 2 laser (upgrade) 150 MeV (120*) * 120Hz beam operation would be an upgrade 6

7 October FACET-II Science Workshop at SLAC Title Speaker Affiliation BIG, a Future Gamma-Ray Source at FACET-II Vitaly Yakimenko SLAC Photonuclear Reactions with MeV-Range Gamma- Rays from FACET-II Norbert Pietralla IKP, TU Darmstadt, Germany ELI-NP: Technology and Physics Potential Dan Filipescu ELI-NP, Romania Low-Energy Nuclear Physics with Laser Compton Gamma-Rays Anton Tonchev LLNL Physics with Low Energy (<100 MeV) Gamma-Rays Blaine Norum University of Virginia, Charlottesville Application of NRF to Nondestructive Assay of Nuclear Materials Laser Requirements for BIG: mid-ir CO2 versus near-ir Ti:Sapph Nuclear Physics with Medium Energy (>100 MeV) Gamma-Rays Ryoichi Hajima Igor Pogorelsky Blaine Norum Japan Atomic Energy Agency BNL University of Virginia, Charlottesville Organizers: Vladimir Litvinenko (Stonybrook) and Carsten Hast (SLAC) 7

8 Low Gamma Energies 8

9 Medium Energy Gammas (Blaine Norum) Range: ~100 MeV Eγ ~ 500 MeV Ø Nucleonic/pionic degrees of freedom Ø Focus on Threshold pion prodution Radiative pion production Other Big Bang Nucleosynthesis- principal reaction chains Neutron Stars Two Nucleons at Nuclear Energies Possible Detectors π-β Detector, JLAB Proton Polarimeter, Vrije University Range Telescope I barely touched on what is possible. Questions range from very fundamental nucleon physics to basic nuclear structure questions Blaine Norum, University of FACET II Science Workshop: Nuclear Physics with Medium Energy (>100 MeV) Gamma Rays 9

10 Parameter List for 1st Mid- and High-Energy Experiments Laser: E~0.5 J; 50 fs; 800 nm; Beam: 2 nc; 3-10 GeV; 30 Hz; 20 µm 3 Nγ = 10 9 /shot or /s (full spectrum) Eγ~ (0.2-2) GeV Modest upgrade: Laser: E~1J; 50 fs; 800nm; (400nm, 266nm), 30Hz Beam: 3-14 GeV; 120 Hz; 20 µm 3 Nγ = /s (full spectrum), Eγ~ (0.2-7) GeV 10

11 High Energy Gammas 0.5 MeV to 7 GeV? 11

12 Gamma Gamma Collider (in a distant future far far away) E e = 4 GeV e - Ε γ ~ 30 MeV, α ~ 0.05 E γcm ~ 1.5 MeV L ~ cm -2 sec -1 e + γ γ e - e + σ γγ->e+e- ~10-25 cm 1.5MeV Will focus on technology research for gamma gamma collider Will test for the first time ability to generate e + e - pairs with real (not virtual) photons This would be the first pair creation test using real photons 12

13 FACET-II User Area Vast variety of experiments ( organically grown ) 13

14 FACET-II User Area 11 feet by 10 feet 14

15 Summary FACET-II will deliver high energy, focused and intense electron and positron beams As a Compton source, BIG s strengths are the very high photon energy, large flux and polarization The experimental area is not very large and relatively difficult to access for very complicated detectors For dedicated experiments BIG could be a real asset for the Community 15