A mathematical model for thermal neutron dosimetry using electrochemically etched CR-39 detectors with (n,p) and (n,α) converters

Abstract

Abstract A methematical model is proposed for a thermal neutron dosimeter using an electrochemically etched CR-39 detector with (n,p) and (n,α) converters. Thermal neutrons produce (n,p) and (n,α) reactions in the nitrogen, boron and lithium constituents of the converter screens used. The protons and alpha particles, generated as a result of thermal neutron interactions, have sufficient energies to produce electrochemically etchable tracks in the CR-39 detector. By using judiciously chosen thicknesses of the converters, and employing proper processing conditions, a practical thermal neutron dosimeter can be constructed. A computer model has been developed to optimize the configuration of the detector/converter assembly, such that it would provide a dose-equivalent response which is of the same order as that for fast neutrons. Finally, a practical design of a dosimeter is suggested that would record the dose equivalent from both thermal and fast neutrons, with comparable efficiency, irrespective of their energies.