Sho Amano, Ken Horikawa, Shuji Miyamoto, Takayasu Mochizuki
SRI 2009: THE 10TH INTERNATIONAL CONFERENCE ON SYNCHROTRON RADIATION INSTRUMENTATION, 1234 495-498, 2010 Peer-reviewed
We have developed a laser-Compton gamma-ray source at beamline (BL1) in NewSUBARU, an electron storage ring operating at electron energies of 0.7-1.5 GeV. Initially, we generated 17-37 MeV gamma rays using a Nd:YVO(4) laser operating at 1.06 mu m and 0.53 mu m, achieving a luminosity of 6000 photons/(W.mA.s) and a flux of 5x10(6) photons/s with a laser power of 4 W and a beam current of 200 mA. We then installed a CO(2) laser operating at 10.6 mu m, and generated gamma rays in the energy range of 1-4 MeV. In this range, the gamma-ray luminosity is 7300 photons/(W.mA.s) and the flux is 5.6x10(6) photons/s when operating the laser at 4 W and 200 mA. These performances are in good agreement with calculations. We will next add a Tm-fiber laser operating at 2 mu m to generate gamma rays in the energy range of 4-21 MeV, using a laser-focusing design to generate the maximum flux. The luminosity of this stage is calculated to be 6400 photons/(W.mA.s). Nd:YVO(4), CO(2), and Tm-fiber laser are all capable of operating in a high-power regime and can generate kW-level output power. At present, the maximum gamma-ray flux is limited only by the laser power. When operating the laser at I kW of output power with a beam current of 200 mA, we expect a flux of up to similar to 10(9) photons/s. At NewSUBARU, up to several dozen MeV gamma-ray sources are capable of generating such high power.