The analysis of dosimetric thermoluminescent glow peak of α-Al2O3 : C after different dose levels by β-irradiation
The variable dose (VD), Tm-Tstop, initial rise, variable heating rate, peak shape and computerized glow curve deconvolution (CGCD) methods were used to determine the number of peaks, the order of kinetics (b), the activation energy (Ea) and attempt-to-escape frequency (s) associated with the dosimetric glow peak of alpha-Al2O3 : C after beta-irradiation at a dose level between 0.02 and 288 Gy. The Ea-Tstop and CGCD methods indicated that the dosimetric peak of this crystal is the superposition of at least two components (peak 2a and 2b). When the dose level reaches and exceeds saturation point, a third peak (peak 2c) is also evident on the low temperature side of the dosimetric peak. The VD and CGCD methods indicated that both components of the dosimetric peak have general-order kinetics that change with doses. The dose responses of peak 2a follow linear, supralinear, saturation and sublinear patterns, whereas peak 2b does not exhibit supralinear behaviour. They are saturated at different dose levels, peak 2a at D = 10 Gy and peak 2b at D = 5 Gy. Ea-Tstop plots obtained at two different dose levels (D = 10 and 1 Gy) indicated that the efficiency of thermal quenching effect on this sample is highly dependent on the dose level and decreases with increasing dose level, which also has pronounced effects on the evaluated kinetic and thermal quenching parameters of the dosimetric peak.
Journal of Physics D Applied Physics
- Pub Date:
- January 2003