Prompt Response Self-Powered Neutron Detectors II: Thermal and Epithermal Sensitivities

A previously developed formalism is applied to calculate the sensitivity of cobalt prompt response self-powered neutron detectors. Differential and average sensitivities in thermal and epithermal energy regions are calculated, and their dependence on the geometrical factors is studied. A simple analytical expression is proposed for the first-collision absorption probability, which is a good approximation to the exact function. This expression is used to obtain the epithermal selfshielding factor as a function of the radius of the emitter and the parameters of the interaction. The thermal sensitivity, as the main contributor to the current, is studied as a function of the emitter radius. Finally, a criterion to evaluate the accuracy of the parameters of the model is established in the form of some interval rule. This interval rule should encourage the performance of better measurements and calculations.