The fission probability of the reaction 232Th(p,p'f) at Esub(p)=52.5 MeV

The relative fission width Psub(f)=GAMMAsub(fission)/GAMMAsub(total) has been measured for the reaction 232Th(p,p'f) up to 32 MeV excitation energy. Above an energy of about 10 MeV the values of Psub(f) were found to increase with energy and reach at 32 MeV a value of about 0.1. The results are explained by a statistical model analysis using Fermi gas level densities and fixing the value of asub(f), the level density parameter for fission, by its appropriate value at the equilibrium deformation. Effective fission barriers are assumed and its heights are adjusted to obtain the experimental fission probability Psub(f) as a sum of contributions of Th-isotopes. The dominant parts seem to come from 232Th and 231Th. (Auth.)