Decay Characteristics of Neutron Excess Selenium Nuclei

The properties of neutron excess selenium nuclei are predicted utilizing a single particle model. The single particle model calculations include alpha, beta, positron, electron capture, and spontaneous fission decay modes. Neutron emission decay modes that have short half-lives are not readily determined by the model. However, estimates of the neutron decay mode were evaluated using the methodology of Chowdhury et al. Using that model, spontaneous neutron emission is predicted to occur in the range of A = 107 – 109. The Japanese Nuclear Data Compilation terminate their calculations at A = 100. Given these results, single particle model calculations are extended to encompass these values, and were extended to A = 104 with closure of the 2d3/2 neutron shell. Single particle model calculations predict that A = 92 – 104 neutron excess selenium systems form bound systems that have limiting beta decay half-lives in the range of 8.50 – 75.3 ms. Model half-life results for the A = 92 – 100 selenium nuclei are within a factor of about 2.6 of the predictions of the Japanese Nuclear Data Compilation calculations.