The impact of nuclear temperature on prompt fission gamma-ray emission
JRC scientists, in collaboration with French, Swedish and Norwegian nuclear research institutions, performed a comparative measurement of prompt fission gamma-ray characteristics for fast-neutron-induced fission of two key nuclei (235U and 238U). The results are important for understanding the competition between neutron and gamma emission in fission and the gamma heating phenomena in Gen IV reactors.
Prompt gamma emission in nuclear fission is one of the least understood parts of the fission process. Therefore, a study was carried out, using for the first time, the new directional neutron source, LICORNE. This source was recently developed by scientists at the French Nuclear Physics Institute in Orsay with support from the JRC-Institute for Reference Materials and Measurements (IRMM). This measurement marks the first step to understanding de-excitation of fission fragments as a function of nuclear temperature.
The data is input to calculations of the de-excitation process in nuclear fission and will help to benchmark the underlying theory. Meaningful theoretical calculations result in high-quality evaluated nuclear data files needed worldwide for precise nuclear heat calculations relevant for future sustainable and essentially CO2-free energy production.