Low Energy Photofission of Heavy Elements—Experimental Results

The status of the photofission data required for nuclear materials assays based on photonuclear reactions is discussed. At Gulf Radiation Technology photofission and photoneutron yield measurements have been done using bremsstrahlung produced with a single section electron linear accelerator. The neutron yield was measured simultaneously with the photofission yield which was measured using solid state track detectors. Preliminary high resolution results have been obtained, using neutron time-of-flight and photodisintegration of deuterium, on the spectrum of thick-target bremsstrahlung used. The fission barrier heights obtained are compared with barrier heights from theoretical analysis of spontaneous fission half-lives.