Influence of Irradiation Rate on the Production of F Centers in LiF (TLD Grade)

Abstract

Optically polished samples of extruded plaques of LiF (TLD grade) were given ⁶⁰Co gamma‐ray exposures ranging from about 35 000–450 000 R, at exposure rates between about 1.5×10³ and 5×10⁶ R/h. Over this range of exposures and exposure rates, the resulting absorption in the F band was found to be independent of exposure rate, and to increase with exposure, even for exposures for which the thermoluminescence exhibited saturation effects. After thermoluminescence readout at about 235°C, practically all the absorption in the F band created by the ⁶⁰Co gamma‐ray exposures had disappeared. These results are compatible with the dominant role given F centers in some of the current models for the thermoluminescence process in LiF (TLD grade).