Post-Neutron Mass Yield Distribution in the Epi-Cadmium Neutron-Induced Fission of ²³⁵U

Cumulative and independent yields of various fission products within the mass ranges of 78 to 117 and 123 to 155 have been measured in the epi-cadmium reactor neutron-induced fission of ²³⁵U by using an off-line gamma-ray spectrometric technique. The average neutron energy <E_n> of the epi-cadmium reactor spectrum is 1.9 MeV. From the cumulative yields, post-neutron mass chain yields were obtained by applying the charge distribution correction. In the mass yield distribution, values of the full-width at tenth-maximum of light and heavy mass wings, average light mass <A_L> and heavy mass <A_H>, and average number of neutrons <ν> were obtained. The peak-to-valley ratio in the epi-cadmium neutron-induced fission of ²³⁵U was obtained for the first time. The present data in the ²³⁵U(n,f) reaction were compared with the literature data in the ²³⁵U(n_th,f) reaction to examine the role of excitation energy on the mass yield distribution parameters and nuclear structure effect. The role of the standard I and standard II asymmetric modes of fission was also discussed.