Spatial frequency analysis of fluorescent nuclear track detectors irradiated in mixed neutron–photon fields

A new image processing method for the dosimetry of mixed neutron–photon fields using fluorescent nuclear track detectors (FNTDs) is investigated. Images obtained from FNTDs were processed using spatial frequency analysis to determine doses for both low and high LET radiations. Spatial frequency analysis extended the dynamic range of detectible neutron doses from 4 orders of magnitude for track counting only to at least 6 orders of magnitude by combining track counting with the new image processing method. Two different converters of indirectly ionizing radiation to secondary charged particles were used in conjunction with image processing to separate signals induced by neutron and gamma fields.