Energy dependence of mass, charge, isotopic, and energy distributions in neutron-induced fission ofU235andPu239

Physical origin of the transition from symmetric to asymmetric fission fragment charge distribution

“…As shown below, the experimental data are well described with this restriction. This restriction was found to simultaneously describe the mass, charge, isotopic and TKE distribution in the 235,238 U(n, f ) reactions at different neutron energies [1]. We note that the value of B q f is defined by the nucleus-nucleus interaction, and is almost independent of the excitation energy.…”

“…The symmetry, Coulomb and surface parts of liquid-drop energy U LD i depends on deformation and excitation energy [1]. The shell corrections are calculated using the two center shell model and the Strutinsky method [2].…”

Physical Origin of the Transition from Symmetric to Asymmetric Fission Fragment Charge Distribution

“…The statistical scission-point model relies on the assumption that the statistical equilibrium is established at scission where the observable characteristics of fission process are formed. The dinuclear system (DNS) model [3,4] is shown to be well-suited for describing the scission configuration. The fissioning nucleus at scission point is modeled by two nearly touching coaxial ellipsoids -fragments of the DNS with masses (charges) numbers A L (Z L ) and A H (Z H ) for the light (L) and heavy (H) fragments, respectively.…”

“…, where E D = 18.5 MeV is the damping constant. The interaction potential consists of the Coulomb interaction potential V C of the two uniformly charged ellipsoids and nuclear interaction potential V N in the double-folding form [3,4].…”

“…In the present paper, the origin of the evolution of the charge distribution with increasing neutron number is studied within the scission-point model [3,4]. The most important ingredient of the model is the potential energy of system as a function of charge (mass) asymmetry, deformations of the fission fragments, and internuclear distance.…”