Systematic studies of fission fragment kinetic energy distributions by Langevin simulations

Abstract

Abstract. Fission fluctuation-dissipation dynamics of heavy nuclei has been studied using Langevin Monte Carlo simulations. The covariant form of the fission transport equation and the coefficients related to it are investigated. To learn about the influence of the dynamics from the ground state to the saddle point on the kinetic energy distributions we have studied various systems and compared the calculations both starting from the ground state and from the saddle point. Both the mean total kinetic energy of the fission fragments and its variances can fit with the experimental values in terms of a finite neck radius as scission condition.

Fission fragment distributions within dynamical approach

“…This parametrization has been also used for static calculations performed with the Strutinsky shell correction method [92], dynamic calculations of MEDs in the diffusion model [12], and for calculating a large number of different fission characteristics in the Langevin approach [19,20,[107][108][109]. The parameter c describes nuclear elongation (the nuclear length, in units of the initialsphere radius R 0 , is equal to 2c), the parameter h defines neck-thickness variation for a given elongation, and the coordinate α sets the ratio between the masses of future fragments.…”

“…The total kinetic energy-distribution parameters have been investigated for various nuclei in a large number of experimental [182][183][184] and theoretical [107,173,185,186] studies. From an analysis of the available experimental data, it was found that E K is virtually independent of both angular momentum and an excitation energy [182].…”

Nuclear scission and fission-fragment kinetic-energy distribution: Study within three-dimensional Langevin dynamics

“…The first two moments of the energy distribution are studied both in many experimental [4,51,60] and theoretical works [18,59,61,62]. Analysis of experimental data shows that the average kinetic energy of fragments E K depends very little on either angular momentum or excitation energy [4].…”

Study of different features of fission dynamics in heavy-ion-induced reactions

“…The last equation means that a part of the Coulomb repulsion energy is used to overcome nuclear attraction between the nascent fragments. It can be estimated as in [31,32].…”