Analytical picture of the effect of temperature treatment on UV and gamma ray sensitivity of CaF2-based TLD

CaF 2 -based TLD treated at high temperature in air exhibit a high intrinsic thermoluminescence to UV radiations. However, this temperature treatment makes them insensitive to ionising radiations. The increase in thermoluminescence sensitivity is shown to be due to the production of oxide at the TLD material surface, whereas the reduction in gamma ray sensitivity is attributed to a change in the nature of impurity atoms responsible for TL emission.