200-MeV bremsstrahlung tagged photon beams at Sendai

A new beam line for photonuclear reaction experiments using tagged photons has been constructed to take advantage of the completion of the 1.2-GeV STretcher Booster (STB) ring at the Laboratory of Nuclear Science (LNS), Tohoku University. A photon tagging system was installed at the end of the new beam line. It provides bremsstrahlung tagged photon beams in an energy range from 0.2E00.2E0 to 0.8E0MeV at the incident electron energy E0E0 with an energy resolution of ΔE/E≈10-2ΔE/E≈10-2. The tagged photon intensity I⩽5×106photons/s is available for typical photonuclear reaction experiments. We introduce the basic parameters of the tagged photons by showing the commissioning data.