Model for Calculating Independent Radiochemical Yields from the Thermal-Neutron Fission ofU235

Abstract

An empirical model was devised to predict independent radiochemical yields from the thermal-neutron fission of ${\mathrm{U}}^{235}$. As much as possible, experimental data were used as a basis for the calculation. The resulting model is best described as a method of correlating the available mass, energy, and yield data in order to predict other quantities, particularly independent radiochemical yields. Calculated radiochemical mass yields, independent yields, kinetic energies, and neutron emission probabilities are compared with experiment. The agreement is generally good. However, the calculation shows a large discrepancy in the energy balance at symmetric fission. Also, it indicates that less than half of the observed gamma-ray energy per fission is accounted for by gamma-ray emission following neutron emission. The results also suggest that even-even fragments are preferentially formed.