Calculation of flat-response fast-neutron detection systems employing finite size BF 3-counters

Abstract

Making the assumption that φ the rate at which neutrons are emitted from a source, is proportional to the volume integral of the slow neutron density throughout the moderator, one can calculate a weighting function ⨍( r) such that ∫ moderator ⨍( r)I( r) dV is proportional to φ where I( r) is the count-rate of a finite size BF 3-counter at position coordinate r . The weighting function ⨍( r) is independent of the energy spectrum of the source neutrons. The calculation is demonstrated by a sample calculation of a flat-response fast neutron detection system.