Kinetic parameters of lithium and aluminium doped quartz from thermoluminescence glow curves

The thermoluminescence (TL) glow-curves of irradiated annealed and non-annealed synthetic β-quartz (Li0.73Al0.73Si1.27O4) synthesised using the ceramic method have been studied. Annealed samples (1200 deg. C for 12 h) exhibit some changes of shape and intensity in the TL glow curves when compared to non-annealed samples in the range of 0.1-5 Gy. These changes can be attributed mainly to thermal alkali self-diffusion through the lattice interfaces involving modifications in the components of the luminescent traps. In non-annealed samples six groups of components at about 100 deg. C, 130 deg. C, 160 deg. C, 210 deg. C, 330 deg. C and 450 deg. C can be found, whereas annealed samples only display one very intense peak at lower temperature (deconvoluted into three peaks at 90 deg. C, 105 deg. C and 130 deg. C) and a lower intensity second wide broad emission at ∼240 deg. C. In this paper, a computerised curve-fitting based on general order kinetics has been used to characterise the glow curve structure resolving trapping parameters for each glow peak: trap depth (E), frequency factor (s) and the order of kinetics (b). The dose dependence of the individual components of the glow curve has been also studied. These data allow us to select the most stable component for use in dosimetric purposes. (author)