Optical absorption and thermoluminescence studies in irradiated dosimetric LiF:Mg,Ti (TLD-100)

The optical absorption (OA) and thermoluminescence (TL) of irradiated LiF:Mg, Ti was studied as a function of the temperature of post-irradiation annealing. The dose response of the OA bands and sensitisation effect were also investigated. The filling and emptying rate 'anti-correlation' and the behaviour with dose of the 5.6 eV and 3.25 eV and 4.0 eV bands lead us to propose that the 5.6 eV band trapping structure actively competes with the 3.25 eV and 4.0 eV bands (or TL peaks 2 and 5) trapping structures in both the excitation and recombination stages and may be the 'deep' competitor responsible for the supralinearity of these peaks. Preferential population of the 2.78 eV band at high ionisation density suggests that this band may arise from a 'two-hit' charge carrier trapping structure. The similarity between the thermal bleaching behaviour of the F band and the 2.78 eV band leads to the suggestion that the 2.78 eV band arises from an F-2 centre.