Theoretical analysis of the probability of 232Th subbarrier fission in a one-dimensional fission model

A theoretical analysis of new experimental data on the probability of 232Th subbarrier photofission is carried out in a one-dimensional fission model. Theoretical fission barriers are approximated by intersecting parabolas. The parameters of the two- and three-humped fission barriers are determined from the fits of the calculated penetrabilities of the fission barriers to experimental values. It is shown that this model can explain the kink in the experimental dependence of the fission-barrier penetrability on the excitation energy at 5.55 MeV, but that it cannot explain the experimentally observed fine structure in the penetrability