Kinetic parameter analysis for the dosimetric peaks of Ca F2:Tm (TLD-300) irradiated with protons and γ-radiations

Abstract

In the present paper, kinetic parameter analysis on high-temperature peaks of proton and γ-irradiated-glow curves by means of the generalized peak shape (GPS) method, the Chen method and the Levenberg-Marquardt method were investigated. In this experiment post-irradiation annealing was used to eliminate the low temperature peaks. The effect of post-irradiation annealing on the kinetic parameters were also studied. According to our study, the kinetic order of peak 5 of TLD-300 should be fractional (between 1 and 2) which is different from first- and second-order peaks in the preceding reports. The effect of post-irradiation annealing on the kinetic parameters of peak 5 is significant. Trap distribution changes due to detrapping and the elimination of the low-temperature peaks during post-irradiation annealing may be used to interpret the drift phenomenon of the trap depth. Kinetic order varies during readout which can be used to explain the drift phenomenon of kinetic order. Other factors such as trap diffusion at room temperature, trapped charge conversion from one type of trap to another and competing non-radiation defects interaction may also affect trap distribution and the corresponding trap depth. The GPS method at γ can be used to evaluate the kinetic parameters of a given peak more precisely than the peak shape method because more data points are involved. The predicted capability of kinetic parameters of the GPS method at γ is inferior to the Chen method as γ increases. This phenomenon can be used to make a judgement as to whether a neighboring peak exists or not.