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 a s a function of the duration of post-irradiation annealing at 165 degr ees C. A post-irradiation anneal at 165 degrees C for 20 min reduces t he intensity of the lower-temperature satellite, peak 4, to negligible levels. The shape of isolated peak 5 changes as a function of the dur ation of the post-irradiation annealing. All three kinetic parameters show important changes as the duration of the anneal increases. Comput erized peak shape analysis shows that the order of kinetics of peak 5 increases from 1.2 +/- 0.05 (1 SD) following a 5 min anneal to 1.72 +/ - 0.07 (1 SD) following a 30 min anneal. The activation energy increas es 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, illus trating the weakness of this criterion for determining the order of ki netics or alternately the breakdown of the cc model applied to peak 5. Our results indicate important structural modifications in the trappi ng structure of peak 5 as a function of annealing time and/or the pres ence of underlying defect reactions leading to these changes in the sh ape of peak 5.