Thermal and Epithermal Sensitivities of Cobalt Self-Powered Neutron Detectors

Thermal and epithermal neutron sensitivities are calculated for cobalt self-powered neutron detectors (SPNDs). Using a reformulation of the analytical model for the calculation of the electric charge produced per neutron captured, a multiple-collision treatment for the calculation of the neutron capture rate is introduced. The calculated values for thermal sensitivities are in excellent agreement with experimental results.,Taking neutron multiple scattering into account, significant differences are found in epithermal sensitivities of cobalt SPNDs with respect to the usual single-collision approximation. It is concluded that the prompt electric current produced in cobalt SPNDs is mainly determined by epithermal neutrons for ₀ ratios >1.3.