Analysis of the cross section for 232Th photofission in the subbarrier energy region

A theoretical analysis of the most detailed experimental data on the subbarrier fission of Th-232 is performed. The energy dependences of the components of the cross sections for photofission through specific channels characterized by the quantum numbers J (pi) K are obtained on the basis of previously measured total photofission cross sections and angular distributions of fission fragments. A theoretical analysis of the subbarrier photofission of Th-232 is performed on the basis of the results obtained for these components. This analysis relies on the one-dimensional fission model within which one assumes a three-humped structure of the fission barrier and introduces damping in the second and third wells by including an imaginary part in the potential used. Values are selected for the parameters of the fission barriers and are compared with similar data from other studies. It is shown that the energy dependences of the photofission cross sections in question can be described adequately.