EPJ Web of Conferences 122, 01003 (2016)
https://doi.org/10.1051/epjconf/201612201003

Dynamical approach to isotopic-distribution of fission fragments from actinide nuclei

¹ Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo, Japan
² Joint Institute for Nuclear Research, Dubna, Russia
³ Kindai University, Osaka, Japan

^a e-mail: chikako@nr.titeich.ac.jp

Published online: 21 June 2016

Abstract

Measurements of the isotope distribution of fission fragments, often denoted as the primary fission yield (pre-neutron yield) or independent fission yield (post-neutron yield) are still challenging at low excitation energies, so that it is important to investigate it within a theory. Such quantities are vital for applications as well. In this study, fragment distributions from the fission of U isotopes at low excitation energies are studied using a dynamical model. The potential energy surface is derived from the two center shell model including the shell and pairing corrections. In order to calculate the charge distribution of fission fragments, we introduce a new parameter η_Z as the charge asymmetry, in addition to three parameters describing a nuclear shape, z as the distance between two centers of mass, δ as fragment deformation, and η_A as the mass asymmetry. Using this model, we calculated the isotopic distribution of ²³⁶U for the n-induced process ²³⁵U + n → ²³⁶U at low excitation energies. As a result, we found that the current model can well reproduce isotopic fission-fragment distribution which can be compared favorably with major libraries.