Compound detector with selective sensitivity to intermediate neutrons

A compound detector based on the23Na(n,γ) reaction in a boron shield is investigated. The detector cross section was calculated assuming that the spectrum inside the shield is a sum of two components, one due to direct penetration of neutrons through the shield wall and neutrons scattered in the shield mass. Also investigated was the effect of hydrolyzing varnish in the shield and the size of the activation detector on the detector readings.