Influence of energy partition in fission and pre-neutron fragment distributions on post-neutron fragment yields, application for ²³⁵U(n_th,f)

University of Bucharest, Faculty of Physics, str. Atomistilor 405, Bucharest-Magurele, Jud. Ilfov, Ro-077125, Romania

^* Corresponding author: anabellatudora@hotmail.com; anabella.tudora@fizica.unibuc.ro

Published online: 26 May 2023

Abstract

The key role in the calculation of post-neutron fragment yields (independent FPY) is played by the pre-neutron fragment distributions Y(A,TKE) and the prompt neutron multiplicity (calculated in the frame of a prompt emission model). The knowledge of excitation energies of fully accelerated fragments is crucial in any prompt emission model. So that the influence on independent FPY of two methods of total excitation energy (TXE) partition, one based on modeling at scission and another on a parameterization at the full acceleration of fragments, and of two reliable Y(A,TKE) data of ²³⁵U(n_th,f) is investigated by using the deterministic prompt emission model with a detailed treatment of sequential emission DSE. The independent FPY results Y(A_p) and Y(Z,A_p) obtained with both methods of TXE partition and both Y(A,TKE) distributions describe reasonably well the experimental data. The use of different TXE partitions and Y(A,TKE) data does not change the positions of the most pronounced peaks and dips in the Y(A_p) structure, only their magnitude is influenced by Y(A,TKE), while the TXE partition influences the position of less pronounced peaks and dips in the structures of Y(A_p) and Y(N_p) (N_p=A_p-Z). The influence of both the TXE partition and the Y(A,TKE) data on different kinetic energy distributions of post-neutron fragments is less pronounced than that on Y(A_p) and Y(N_p)