Cumulative short-lived photofission product yields for nuclear forensic application

摘要

Short-lived products reported for ~(238)U and ~(232)Th for 3 energies, reported with both endpoint and excitation energies to allow for comparison. CFPYs for 20 MeV good agreement with DT neutron fission CFPYs for 14 and 8 MeV reflect expected distribution using the ENDF-B/Ⅶ.0 fractional mass yields and multi-mode fission model. Due to the lack of evaluated experimental data for photofission product yields, ENDF-B/VII.O neutron fission cumulative fission product yields for fast (500 keV) and DT (14 MeV) neutron fission were used as the primary comparison to the measured photofission yields. There are few published photofission product yields for low (≤12 MeV) excitation energy photofission product yields, so future work looking at photofission excitation energies with comparable excitation energies of thermal, fast, and DT neutron fission would be of considerable value.