Thermoluminescence studies of LiF (TLD-100) in the temperature interval 10–300 K

LiF (TLD-100) has been investigated by thermoluminescence (TL) techniques in the temperature interval 10–300 K. Emission spectra data, in conjunction with thermal annealing, photobleaching, and optical repopulation studies, support the model previously proposed by Cooke to explain the TL mechanism in TLD-100 over the temperature range of 90–500 K. By extending the studies to 10 K, six new glow peaks have been observed; maxima occur at 20, 44, 60, 66, 84, and 124 K. The latter peak represents a shoulder on the intense glow peak occurring near 138 K (previously reported) and is attributed to the thermal release of trapped electrons. The remaining peaks are associated with the thermal detrapping of shallow trapped holes which produce 400-nm band emission. By incorporating the existence of shallow trapped holes into the existing model we present a band-gap model which depicts the TL mechanism in TLD-100 valid in the temperature interval 10–500 K.