High-energy photofission cross sections of uranium and thorium

Abstract The photofission cross sections per equivalent quantum of uranium and thorium have been measured in the bremsstrahlung energy range 200 to 900 MeV. A glass detector was used to detect the fission fragments. Fission cross sections are obtained from the integrated cross section using Penfold and Leiss's method. It is found that the photofission cross sections of both uranium and thorium show resonance peaks at a photon energy of 350 MeV, with peak values of 80 and 60 mb respectively. It is suggested that in a high-energy photofission, the fission mechanism can, at least in part, be due to photomeson production processes.