2024/04/26 by Futoshi Minato, Minato, Futoshi, Osamu Iwamoto +1
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Nuclear Materials and Properties #Nuclear Theory (nucl-th) #Nuclear physics research studies #Nuclear reactor physics and engineering
paper · pdf · doi:10.48550/arxiv.2404.17728
openalex publication_date 2024/04/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Fission fragment yield evaluations are one of the important nuclear data studies. Fission accompanies various physical observables such as prompt fission neutron, prompt fission gamma, and delayed-neutrons. When evaluating fission fragment yields, a study including correlations among those observables is essentially required. However, fission fragment yield data in the past JENDL libraries have been made by focusing only on experimental fragment yields, decay heats, and delayed neutron yields, and they have not been expanded into a wider range of fission observables. This is because the evaluation method adopted in the JENDL libraries could not study fission fragment yields and particle emissions from fragments simultaneously. To solve this problem, a calculation system with CCONE code is newly developed to estimate not only independent and cumulative fission fragment yields but also prompt fission neutron, prompt fission gamma, decay heats, and delayed-neutrons simultaneously. This system enables us to study a correlation between various fission observables. To determine lots of parameters in this system efficiently, a Gaussian process and a least square fitting are adopted. We tested the calculation system through a thermal neutron-induced fission on 235U. In this paper, we demonstrate the performance of the parameter search method and show that experimental fission fragment yield data and other observables resulting from fission are reproduced well by the new calculation system.