Neutron dosimetry based on chemical etching of proton tracks in CR-39

The response of CR-39 from different manufacturers to alpha particles, protons and neutrons of different energies has been analysed using two-step chemical track etching. The track density in the detector after neutron irradiation is determined by the secondary charged particle production cross sections, the detector sensitivity to these particles, and by the depth in the detector. The nature of the dependence of detector efficiency on the depth in the detector varies with the neutron energy spectrum and the angle of neutron incidence to the detector surface. The possibility of using this effect to obtain the neutron spectrometric information was proved. Detectors were exposed to neutrons of energies 3 MeV and 14 MeV at different angles of incidence. The secondary proton track densities were evaluated for two configurations, e.g. detectors with and without the polyethylene radiator. For suppresion of spurious track density accumulation, the etching mode insensitive to protons was adopted in the first etching step. After removing the desired detector thickness, the etching was continued in the conventional manner. The changes in detector sensitivity at various detector depths were observed in some detectors tested. (author)