Thermoluminescence kinetic analysis of quartz with a glow peak that shifts in an unusual manner with irradiation dose

Thermoluminescence kinetic analysis using Tm-Tstop, glow curve deconvolution, variable heating rate and repeated initial rise methods have been carried out on the glow curves of a quartz with a glow peak whose peak temperature goes through a peak as a function of irradiation dose, an unusual feature for quartz. The glow curve of the sample showed four clear glow peaks around 82 deg. C (peak I), 148 deg. C (peak II), 200 deg. C (peak III) and 292 deg. C (peak IV) when irradiated to 1.8 Gy and read out at 1 deg. C s-1. The peak temperature of peak IV first increases and later decreases with dose whereas the peak temperatures of peaks I, II and III are independent of dose. Tm-Tstop and glow curve deconvolution (GCD) analyses indicated the presence of at least five peaks at about 80, 146, 199, 295 and 350 deg. C meaning that the apparently single peak IV may consist of at least two overlapping glow peaks. The activation energy, E, and frequency factor, S, associated with each of the glow peaks are presented. E and Tm values for all the glow peaks in the quartz sample were found to be dose-independent. It was also found, during the use of GCD, that as the irradiation dose increases, the number of thermoluminescence (TL) peaks required to produce the best fit to the glow curve increases although the location of the TL peaks themselves does not change with dose. This effect is explained in terms of the relative intensities of the glow peaks. We have also noted that the ability of GCD to completely isolate all the glow peaks in a glow curve may depend on irradiation dose