Linearly Polarized Quasi-monochromatic Photon Beams From Compton Backscattering Of Laser Lights At ETL

Linearly polarized quasi-monochromatic photons have been generated by Compton backscattering of linearly polarized laser beams against the relativistic electrons in a storage ring. The polarized photon energy ranges from 1 to 20 MeV by using the Nd:YAG laser and the 250-750 MeV electron storage ring TERAS at ETL. When we change the laser polarization axis in a high repetition rate to change the polarization axis of the Compton backscattering photon, we can measure the polarization of the Compton backscattering photon with a single detector. The polarization of the backscattering photon beam has been measured with a Compton polarimeter consisting of a single detector. Almost completely polarized photon beam can be confirmed with this system.