The photofission of 238U

Abstract

The fragment mass yield distributions from the photofission of 238U induced by 33 MeV bremsstrahlung have been measured for various ranges of total fission fragment kinetic energy release. The fragment energies were detected with semiconductor detectors and the fragment mass obtained by the analysis of the coincident energies with an analogue ratio circuit. The variations of the most probable mass ratio m H / m L and of symmetric mass yield, with average total fragment energy release, are discussed in terms of the fragment shell theory and the two mode hypothesis. The data are consistent with both theories.