REVIEW OF DOSE-RATE EFFECTS IN THE THERMOLUMINESCENCE OF LiF: Mg, Ti (HARSHAW)

The literature describing the experimental investigations of possible dose-rate effects in the thermoluminescence (TL) of LiF: Mg, Ti (Harshaw) is reviewed. The total lack of glow curve analysis, coupled with inclusion of all or part of the high temperature TL and absence of parallel measurements of possible dose-rate effects in the irradiation stage severely limit the scientific and technical level of the experiments. In addition, the experimental procedures are far from sufficient to warrant any conclusion concerning the presence or absence of dose-rate effects in the TL of LiF: Mg, Ti. This decision is contrary to the widely held belief that there are no dose-rate effects in the TL of LiF: Mg, Ti. In addition, the literature on dose-rate effects in the optical absorption (irradiation stage) of LiF is reviewed and is found contradictory. No dose-rate studies have been carried out on optical absorption in LiF: Mg, Ti. Kinetic simulations demonstrating the possibility, even likelihood, of dose-rate effects are also reviewed. Dose-rate effects are shown to be likely due to competition between excitation and recombination in the irradiation stage. Some other possible mechanisms involving multiple charge carrier trapping are suggested. Further definitive experiments are sorely needed, but the interested researcher should beware, it is not an easy task.