Post-Neutron Mass Yield Distribution in the Epi-Cadmium Neutron–Induced Fission of ²³⁸Pu

The cumulative and independent yields of various fission products within the mass range of 78 to 157 have been measured in the epi-cadmium neutron–induced fission of ²³⁸Pu by using an off-line γ-ray spectrometric technique. The lower yield of ¹³⁶I than the usual trend indicates the formation of delayed neutron emitter ¹³⁷I. From the cumulative yields, post-neutron mass chain yields were obtained by using the charge distribution correction. From the mass yield data, the peak-to-valley (P/V) ratio, the full-width at tenth-maximum of light and heavy mass wings, the average light mass <A_L> and heavy mass <A_H> as well as the average number of neutrons <ν> emitted were obtained. The mass chain yield data in the ²³⁸Pu(n,f) reaction were compared with similar data of the ²³⁸Pu(n_th,f) reaction to examine the role of excitation energy on the nuclear structure effect and P/V ratio.