Determination of cross sections for the ⁸⁰Kr(<i>n</i>, 2<i>n</i>)⁷⁹Kr reaction in the neutron energy range of 13−15 MeV*

Abstract In this study, neutron activation experiments were performed to measure the ( n , 2 n ) reaction cross section for 80 Kr at five neutron energies, 13.59±0.12, 13.86±0.15, 14.13±0.16, 14.70±0.13, and 14.94±0.02 MeV, using a highly enriched gaseous sample. The neutron energies and their uncertainties were determined using the Q -value equation for the 3 H( d , n ) 4 He reaction, accounting for the solid angle of the sample. The 93 Nb( n , 2 n ) 92m Nb reaction was employed to monitor the neutron flux. Eight characteristic gamma rays of the produced nucleus were selected to determine the activity of the generated nuclei. The final cross sections were obtained using a weighted average method. The self-absorption and cascade of rays, as well as the geometry and solid angles of the sample, were corrected. The 80 Kr( n , 2 n ) 79 Kr reaction cross sections obtained in this work exhibited the smallest uncertainty than the values in existing literature, which provided improved experimental constraints for the prediction of excitation curves, thereby enhancing the quality of the corresponding database. The measured results were compared with previously reported experimental values, empirical and systematic formula predictions, theoretical calculations from TALYS-1.96 with six adjustable energy level densities, and evaluated database results. Our experimental results demonstrated high precision and extended the energy range appropriately, offering valuable insights for future studies.