Energy partition between splitting fission fragments

Abstract

From the microscopic view, the energy partition between two fission fragments are associated with the splitting of wave functions of an entangled fissioning system, in contrast to most fission models using an explicit statistical partition of excitation energies by invoking level densities of fragments. The dynamical fission evolution is described within the time-dependent Hartree-Fock+BCS framework. Excitation energies of isotopic fission fragments are obtained with the particle-number projection method after the dynamical splitting of $^{238}$U. The resulting excitation energies of light and heavy fragments illustrate the appearance of sawtooth structures. We find that the paring strengths have significant influences on the partition of excitation energies. Furthermore, excitation energies of isotopic fragments increase with increasing neutron numbers, suppressing the production of neutron-rich beams in rare-isotope beam facilities.