Cooling rate effects in the thermal and optical excitation of LiF:Mg,Ti

The effects of cooling rate following the 400 °C pre-irradiation anneal on the structure of the TL glow-curve of LiF:Mg,Ti and the optical conversion of peak 5a→4 following beta irradiation are investigated in both “slow-cooled” and “naturally-cooled” samples. Computerised glow curve deconvolution is employed with constrained “peak-shape” parameters deduced from anciliary studies using 4 eV and 5 eV optical excitation. It is demonstrated that “slow-cooling” using linear cooling rates of 100 °C/h and 30 °C/h increases the intensity of glow peak 5a and decreases the intensity of peaks 4 and 5 relative to the normal/rapid cooling rates. Serendipitously, the conversion efficiency of peak 5a→4 at a cooling rate of 100 °C/h is found to be ∼ unity indicative of an approximate one-to-one correspondence between the peak 5a and peak 4 configurations.