Fission-product gamma-ray line pairs sensitive to fissile material and neutron energy

摘要

The beta-delayed gamma-ray spectra from the fission of ~(235)U, ~(238)U, and ~(239)Pu by thermal and near-14-MeV neutrons have been measured for delay times ranging from 1 min to 14 h. Spectra at all delay times contain sets of prominent gamma-ray lines with intensity ratios that identify the fissile material and distinguish between fission induced by low-energy or high-energy neutrons.