Detection Efficiency of Bare and Moderated BF3-Gas-Filled Proportional Counters for Isotropic Neutron Fluxes

Abstract

An elaborate calibration of BF3-gas-filled proportional counters with and without moderator was made for isotropic neutron fluxes. The effective sensitivity of a hare BF3 counter in a nondiffusing medium was determined by means of a calibrated indium foil. The flux-depression effect in a diffusing medium was experimentally evaluated. Details of the experimental techniques and results are described. For the measurement of fast neutrons, energy dependence of sensitivity of two differently moderated counters was determined in the energy region from 1 eV to 10 MeV. Angular dependence of sensitivity of the moderated counters and its dependence on neutron energy are also described. © 1966 Taylor and Francis Group, LLC.