PRODUCT YIELDS FOR THE PHOTOFISSION OF 238U, 237Np AND 239PuCyclotron and Radioisotope Center, Tohoku University Aramaki, Sendai-shi, Miyagi 980, Japan Sheiichi Shibata Institute for Nuclear Study, University of Tokyo Midori-cho 3-2-1 Tanashi-shi, Tokyo 188, Japan This paper shows the absolute yields for the mass distribution of photofission products of 238U, 237Np and 239Pu. The thin targets of 238U, 237Np and 239Pu were irradiated with the bremsstrahlung beam whose end-point energy was 20-, 30- and 60-MeV. Fission fragments recoiled out from the target were catched on the aluminum foil. The mass-yield distributions of fission fragments were obtained by measuring gamma-ray activities with a pure-Ge detector. Our mass distribution curves showed good agreement with the other experimental results. KEYWORDS: photofission, cross section, bremsstrahlung, mass distribution, 238U, 237Np, 239Pu |