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Advanced Photons and Science Evolution 2010 June 14-18 , 2010, Osaka Japan. Medium and High Energy Photons for Nuclear Particle Physics. Schin Daté Accelerator Division, SPring-8/JASRI. Previous talks which includes laser backscattering g beamlines.
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Advanced Photons and Science Evolution 2010 June 14-18 , 2010, Osaka Japan Medium and High Energy Photons for Nuclear Particle Physics Schin Daté Accelerator Division, SPring-8/JASRI
Previous talks which includes laser backscatteringg beamlines T. Shima: New Subaru Y. Ohashi: LEPS/LEPS2 W. Tornow: HIgS W.C. Chang: LEPS M. Niiyama: LEPS/LEPS2
My talk: Additional options to future backscattering g beamlines I. High Energy g Production in SPring-8 II. Intense 10 MeV g Production in Light Sources
Choice of Undulator Portion of the fundamental= kG
˙ N d ph / I e d w † Yield of X-ray photons ( )
Can s be mm2 ? Re-focussing Thin undulator approximation 275x2 mm ~100 mrad e- 6x2 mm spherical mirror In principle, yes.
Bunch mode dominance 60 cm 100 mrad . . . e- h ~ 275 mm v ~ 6 mm
. , : reinjection efficiency for . = 100 mA/e Yield of High Energy Gamma 50% Notation: , Undulator (K=5~6, l =1.1 m,4 periods) Electron beam emittance + re-focussing Beam current:
Summry of part I • Provided • an undulator with • high reflectable (R > 0.5)spherical mirror for 100 eV photons • with timing adjustment system (mirror position z = 24 +- 2 m, dz = 6mm) We may obtain in principle. The number may increase by an order of magnitude for the future refinement of the storage ring.
~ flat (1) Energy , (2) Angle , (3) Controlled Polarization I = 100 mA l = 10 m = 0.5 b Well known facts about Compton back scattering (4) Yield for
f15mm core Single mode CW output power (W) year Yb fiber laser (IPG): 1030 ~ 1050 nm CW single mode 2 kW multimode 20 kW Progress in laser technology Fiber Laser bundled fiber line of, say, cmf is possible to make Heat load limit ~ 20 MW / mmf 100 kW output is cleared in this way Polarization?
(1) Enegy aperture 2. Production of Intense 10 MeV g Rays
= (2) Longitudinal beam quality I = 100 mA No serious effect on the longitudinal beam quality
Summary of Part II There is no crucial problem to producee very intense (~ 10^11 /s) 10 MeV gamma rays in 3 GeV light sources including CLS, MAX IV and NSLS-II.. There are technologies available to realize the intense gamma production. Now is the adequate time to consider such a possibility seriously.
Conclusion I. We may think seriously about quasi-monochromatic g beamline with Eg_max ~ Ee and Ng ~ 10^6 /s as an option to future beamlines in high energy synchrotron light sources. II. There is no crucial problem to producee very intense (~ 10^11 /s) 10 MeV gamma rays in new 3 GeV light sources.
Why Do We Want 10^11 /s Photons? Because many interesting elementary interactions occur with s ~ pb r = 10 g / cm^3 l = 1 cm s = 1 pb for
<s x’>BCS ~ 64 mrad 3.4 10-9 ey ( ex ) ex = m rad , = 0.2 % g beam divergence <=> • beam divergence in LSS BL is dominated by Compton scattering. Contributions are wighted for Gaussian laser beam. <= Values are valid for the laser waist radius > 0.5 mm.