Simulation of peak properties in thermoluminescence dosimeters with the potential stimulation of all electron traps

Abstract

In thermoluminescence (TL) models, the competition between energy levels for electron trapping is a direct consequence of conduction band mediation in electron transport. From a theoretical perspective, these competitive effects are considered responsible for many TL phenomena. Furthermore, while they are easily detectable in simulation studies, there are no clear and reliable criteria for their experimental verification. In the present work, it is suggested that in certain materials with narrow band gap energies, existing electron traps can be accessed by thermal stimulation up to 500 °C. It is possible to predict properties through simulation that can then be verified experimentally. The simulation is applied to a complex TL glow curve consisting of four electron trapping levels and one luminescence center. With the appropriate selection of simulation parameter values, the competition is limited solely to electron transport, rather than to significant differences in parameter values. The simulation indicated that the last peak serves as the primary competitor. Furthermore, the shape of the TL glow curve depends on the strength of the competition. When the competitor is strong, the lower temperature peaks behave as first-order peaks, and the shape of the glow curve remains stable as a function of dose. The last peak, which acts as the final competitor, exhibits behavior similar to that of the peak derived from the one trap, one recombination (OTOR) model. This OTOR-like behavior provides an excellent experimental test for the simulation results and, consequently, for the model used. The validity of the simulation was assessed by comparing the input values of kinetic parameters with the output values obtained from computerized glow curve deconvolution (CGCD) analysis for each TL glow curve.