Gary W. Phillips, Jerrette E. Spann, James S. Bogard, Tuan VoDinh, Dimitris Emfietzoglou, Robert T. Devine, Marko Moscovitch; Neutron spectrometry using CR-39 track etch detectors. Radiat Prot Dosimetry 2006; 120 (1-4): 457-460. doi: 10.1093/rpd/nci675
Track-size distributions were measured for chemically etched CR-39 foils exposed to monoenergetic neutrons with energies ranging from 0.144 to 19 MeV and to various broad-spectrum neutron sources including spontaneous fission neutrons from 238Pu. These tracks are due to energetic charged particles resulting from interactions of the neutrons with the CR-39. The tracks are visible with an optical microscope after chemical etching and vary in size and configuration depending on the particle, energy and angle of incidence. The foils were analysed using an automatic analysis system that scans the foils, identifies valid tracks and records the track-size parameters. The track-size distributions vary with neutron energy for the monoenergetic sources and with the hardness of the broad-spectrum sources. The distribution from the 238Pu fission source is readily distinguishable from the other sources measured and from distributions owing to the background.