Effects of high ambient temperature on glow-peak fading properties of LiF:Mg,Ti thermoluminescent dosemeters.

The effects of a controlled high temperature environment on LiF:Mg,Ti thermoluminescent dosemeters (TLDs) were investigated. TLDs were exposed to ambient temperatures of 30, 40 and 50°C. Sensitivity changes before irradiation, typically called pre-irradiation fading, and signal loss after irradiation, called post-irradiation fading, were studied. Dosemeters were subjected to up to 33 d of pre-irradiation and 68 d of post-irradiation storage. For pre-irradiation fading, peak 5 showed a signal increase of ∼30 % and peak 4 showed an ∼30 % decrease in 20 d. The sum of the areas of peaks 4 and 5 remained relatively constant even for long pre-irradiation times, although at 50°C, losses in peak 5 signal were too significant to maintain the sum of peaks 4 and 5 constant. Peak 3 was still detectable even at 50°C and the longest irradiation times, but peak 2 was very difficult to detect after 15-20 d, especially with post-irradiation fading.