Determination of CR-39 detection efficiency for fast neutron registration and the absolute neutron dosimetry

Abstract

In this work, the efficiency η of CR-39 track detector for fast neutron registration was measured and compared with the calculated one. η was defined as the ratio of induced proton tracks in CR-39 detector to the incident neutron flux taken into account the neutron scattering cross-section of the reaction. In this study, a 5 Ci 241Am–Be cylindrical shaped neutron source was used and different theoretical approaches for flux evaluation were considered. It was found that at small source-to-detector distances (⩽90 cm) the cylindrical source configuration should only be considered in neutron flux calculations and absolute dosimetry evaluation. Also, a good agreement between the calculated and the measured values of η has been found. Moreover, calculated neutron doses have shown excellent agreement with those measured by track detectors and by a Secondary Standard Neutron Monitor.