Energy dependence of Vp for 233U, 235U and 239Pu below 5.0 MeV.

Abstract

Measurement were made of the energy dependence of Vp for neutron induced fission of 233U from thermal to 2.0 MeV. An analysis has been made of all existing data below 5 MeV for 233U, 235U and 239Pu. It is observed from this analysis that the energy dependence of Vp for all three nuclei may be characterized by a two line dependence in which the change of slope occurs at the pairing energy. The nature of the Vp(En) dependence is explained in terms of the double-humped fission barrier and is consistent with the adiabatic assessment of weak coupling of the collective degrees of freedom at the saddle point to the nuclear degrees of freedom at scission.