Abstract
Data are presented that demonstrate the concept of a fast neutron dosimeter using cooled optically stimulated luminescence. A powder calcium fluoride:manganese, compounded with polyethylene, was injection-molded and pressed into 0.1-cm-thick sheets. The sheets were then cut to form dosimeters with dimensions 1.25 × 1.25 cm. After laser annealing, the dosimeters were exposed to various amounts (from 10 to 100 millisieverts) of fast 252Cf neutrons. The exposed dosimeters were cooled to liquid nitrogen temperature, stimulated with laser light, and then allowed to warm up to room temperature. The dose-dependent luminescence was then recorded with a photon counting system. When the control and gamma components were subtracted from the 252Cf response, a dose-dependent neutron response was observed. The design, construction, and preliminary performance of an automated system for the dose interrogation of individual calcium fluoride:manganese grains within the polyethylene matrix will also be discussed. The system uses a small carbon dioxide laser to heat areas of the cooled dosimeter to room temperature. If the readout of very small grains within the plastic matrix is successful, it will enhance the neutron to gamma response of the dosimeter.