Recent enhancements to the understanding of the response of the NRPB neutron personal dosemeter

The response of the NRPB neutron personal dosemeter has been determined for intermediate energy neutrons using the code MCNP. These calculations fill the energy gap for which it is difficult to obtain calibration fields, and thereby enable the response function to cover the energy range from thermal to 15 MeV in an effectively continuous fashion. Recent free-in-air irradiations of the dosemeter around its fast neutron threshold have enabled the energy dependence of response in the 100 keV–1.2 MeV energy range to be determined with high resolution. The effect of performing these irradiations free-in-air has been investigated using monoenergetic irradiations and MCNP calculations.