The Analysis of Thermoluminescent Glow Peaks in CaF<sub>2</sub>:Tm (TLD-300)

Abstract

Computerised glow curve fitting, the variable heating rate method, Tm-Tstop procedure and the dose variation method are used to determine the number of peaks, the order of kinetics, the activation energy E and the attempt-to-escape frequency s associated with the glow peaks in single crystals of CaF2:Tm (TLD-300). Dose variation and the Tm-Tstop procedure indicate that there are only first-order kinetic TL processes in the temperature range from 300 K to 600 K. Glow curve analysis indicates that the glow curve in this temperature range can be best described as a superposition of six peaks. Trapping parameters found with glow curve fitting are found to be constant for glow curves measured at heating rates varying from 0.24 K.s-1 to 3.0 K.s-1. Glow curve fitting and the variable heating rate method yield trapping parameters for main peak 3 which agree reasonably well (E = 1.15 ± 0.02 eV and 1.22 ± 0.04 eV respectively). For all other peaks there is no, or doubtful, agreement. The discrepancy may be caused by the presence of several emission bands at different wavelengths. The possibility of using computerised glow curve analysis in obtaining more information on the radiation quality in mixed radiation fields is discussed.