STUDIES ON THE PHYSICAL CHARACTERISTICS OF THE TLD-LiF DOSIMETERS
Tehran University, Science Faculty, Physics Department
Kargar Avenue, Tehran, IRAN
I have investigated the physical characteristics of the TLD-LiF 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, where powder, discs and rods were used for the dose levels 0.5 mGy up 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.
Reusability after annealing, washing, and the sterilization did not significantly affect these dosemeters response and very little effect on the ideal energy dependence were observed.
Glow curves stability was also investigated by using 90Sr source exposure and heating at 300°C for reading. The hight of the glow curves were increased linearly by the increment of the time of exposure (radiation exposure).
The desirable physical specifications of TEFLON used with excellent characteristics of the TLD-LiF makes it a small, simple, reusable and mechanically flexable dosemeter which has a density close to the body tissues.
KEYWORDS: Build-up, Backscatter, Radiation Response, Energy Dependence, Fading, Tribother-moluminescence, High Exposure.