Neutron proportional counter design for high gamma-ray environments

A parametric analysis of the performance of 3He neutron proportional detector tubes in mixed gamma-ray/neutron environments has been performed. The objective of this study was to determine the optimum tube design configuration for minimized gamma-ray sensitivity based upon commercially available components. The parameters examined in the study were the tube wall material, the admix gas identity, the total fill pressure, and the tube lining material. The study resulted in the quantification of the limitations of typical 3He tube designs and in the development of a new tube design which extends the usefulness of 3He tubes in mixed gamma-ray/neutron environments.