Speaker
Description
Accurate fission product yield (FPY) data are essential for various applications, including reactor antineutrino spectrum calculations. However, experimental FPY data remain incomplete due to the difficulty of measuring short-lived fission fragments. Meanwhile, theoretical models have provided qualitative insights into the fission process but still lack sufficient accuracy for quantitative predictions. To address these limitations, we developed a semi-empirical model to improve FPY predictions.
Our study treats the compound nucleus as a microcanonical ensemble, assuming that FPYs are proportional to the level density at the fission barrier. The potential energy at the fission barrier is modeled as a combination of a macroscopic component following the liquid drop model and a microscopic component arising from shell effects, represented as a parabola and a Gaussian function, respectively. The parameters for these components were determined using experimental data.
To properly describe the fission process, we devised a method where the pre-neutron emission FPY is reproduced using the semi-empirical model, followed by the construction of a probability distribution for neutron emission from fission fragments based on neutron multiplicity, ultimately allowing us to calculate the post-neutron emission FPY.
Acknowledgement: This work was supported by KAERI Institutional Program (Project No. 524560-25) and the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIT)(No. RS-2024-00436392).
