Computerized glow curve deconvolution applied to the analysis of the kinetics of peak 5 in LiF:Mg,Ti (TLD-100)

The kinetic parameters of peak 5 in LiF:Mg,Ti (TLD-100) were studied as a function of the duration of post-irradiation annealing at 165 degrees C. A post-irradiation anneal at 165 degrees C for 20 min reduces the intensity of the lower-temperature satellite, peak 4, to negligible levels. The shape of isolated peak 5 changes as a function of the duration of the post-irradiation annealing. All three kinetic parameters show important changes as the duration of the anneal increases. Computerized peak shape analysis shows that the order of kinetics of peak 5 increases from 1.2+or-0.05 (1 SD) following a 5 min anneal to 1.72+or-0.07 (1 SD) following a 30 min anneal. The activation energy increases from 1.75 eV after annealing for 5 min to 2 eV after annealing for 15 min and then remains constant for longer annealing times. However, the position of isolated peak 5 (T max ) does not vary with dose, illustrating the weakness of this criterion for determining the order of kinetics or alternately the breakdown of the GO model applied to peak 5. Our results indicate important structural modifications in the trapping structure of peak 5 as a function of annealing time and/or the presence of underlying defect reactions leading to these changes in the shape of peak 5.