A New Passive Dosemeter Using an Imaging Plate and Annealing

Abstract

A new passive dosemeter for γ ray monitoring has been developed using an imaging plate (IP), combined with a unique annealing process. In the application of IPto dosemetry, fading causes serious problems. The fading is considered to be caused by the recombination of holes and electrons trapped shallowly in the F centers, which have several activation energies. Appropriate post-irradiation annealing procedures allow elimination of trapped charges with low activation energies, and quantitative estimation of the radiation dose is possible. With the optimum annealing condition experimentally established to minimize the effect of fading on dose estimation, it has become possible to evaluate a one-month dose directly with reasonable accuracy from the photo-stimulated luminescence (PSL) density of the annealed IP.
With the described dosemeter, a one-month integral dose was measured in practice at several locations over the period of one year. The results were compared with those obtained using a commercially available optically stimulated luminescent dosemeter.