Calculation of the energy dependence of fission fragments yields and kinetic energies distributions for neutron-induced 235U fission

Abstract

Fission fragments yields and average total kinetic energy are the fundamental nuclear data essential for applications in nuclear energy and the study of nuclear devices. Certain fission products, such as 95Zr, 99Mo, 140Ba, 144Ce and 147Nd, serve as burnup monitors, assessing the number of fissions induced by neutrons on 235U. However, current experimental data for these fission products worldwide are inconsistent, introducing significant uncertainty into related scientific research. This study employs the Potential-driving Model to calculate the independent yields of 235U and evaluates its advantages in such calculations. Additionally, we investigate the energy dependence of independent yields for select important products. Furthermore, we calculate the cumulative yields of 95Zr, 99Mo, 140Ba, 144Ce, and 147Nd, and compare them with existing literature data to explore the energy dependence of fission products for 235U. Given the lack of fission product yield data above 14.8 MeV, we extend our calculated incident neutron energy to 20 MeV, aiming to support future scientific research. The Geant4 physical model does not consider the influence of incident neutron energy on the average total kinetic energy of fission fragments; thus, we introduce the excitation function of the total kinetic energy of fission fragments recommended by Madland et al., which effectively describes the experimental data of the average total kinetic energy of fragments formed in 235U fission. This study offers a detailed discussion on the energy dependence of fission product yield and average total kinetic energy.