Thermal-Neutron Flux Distribution in Cubical Cavities from an Isotopic Neutron Source

The thermal-neutron flux magnitude and distribution were measured in large cubical cavities for a bare and paraffin-covered ²⁴¹Am-Be neutron source situated in the center. The flux at a specific location in each cavity was found to be proportional to the inverse surface area of the cavity. The thermal-neutron flux/fast-neutron flux at each location was found to be essentially constant for the range of cube sizes under study.