Studies on the physical characteristics of the TLD-LiF dosemeters

An investigation has been carried out of the physical characteristics of lithium fluoride thermoluminescent dosemeters (TLD-LiF) in the form of Chips, Powder, Discs and Rods with 30%, 100%, 30% and 8% Lithium Floride by weight, respectively. TLD-LiF chips were used for glow curve studies, and powder, discs and rods were used for dose levels 0.5 mGy to 10 mGy. The accuracies were found to be ± 15%, ±10% and ±3% for the dose levels of 0.5 mGy, 5 mGy and 10 mGy, respectively. Annealing, washing and sterilization did not significantly affect the response of these dosemeters and very little effect on the ideal energy dependence was observed. Glow curves stability was also investigated by exposure to a 90Sr source and heating at 3000C for reading. The height of the glow curves increased linearly to the time of exposure to radiation. The desirable physical specifications of TEFLON combined with the excellent characteristics of the TLD-LiF makes it a small, simple, reusable and mechanically flexible dosemeter which has a density close to body tissues. (author)