Excitation of Energy Levels of Fissionable Nucleus Shape Isomers in the Doorway State in Reactions with Neutrons and Deuterons

Measurements were conducted for the fission neutron yields with fission fragments in the (d,pf) reactions at some excitation energies, where threshold neutrons were discovered. These data on the neutron yields in 233U(d,pfn) and 239Pu(d,pfn) reactions have been compared with the dependence of the average of fission neutrons vp(En) in the 233U(n,f) reaction as well as fission probability in the 239Pu(d,pf) reaction on excitation energy, which provides a better understanding of the nuclear fission process in a (d,pf) reaction and the vp(En) dependence on neutron energy.