Title: Development of High-Power .GAMMA.-Ray Source by Compton Scattering.
Abstract: We have investigated the Compton scattering of an intense laser beam confined to the supercavity for a highenergy and high-bright photon source. To generate the scattered photons in high efficiency, it is necessary to collide high-density electrons with high-density photons. Therefore, the laser light and the electron beam should be focused as small as possible to get intense radiation. But the focused laser beam and electron beam cannot overlap with each other completely. Here we describe a method for an electron beam and laser beam to interact under optimal conditions in a realistic case. Using this method, we can estimate the flux of γ-ray 1012 photons/sec for a conventional laser with a supercavity and typical electron storage ring.