Non-monotonic dose dependence of thermoluminescence in spatially correlated systems

Abstract

TL dose dependences were simulated following the semi-localized transitions (SLT) model and the model with cluster defects which contain TL-active electron traps, luminescence centers and deep hole traps. Monte-Carlo method was used to calculate cluster occupancy at the irradiation and relaxation stages. At the heating stage, TL yield was calculated with Monte-Carlo method and with the proposed analytical approach. This approach expressed TL yield via cluster occupancy after relaxation stage. The results showed that non-monotonic dose dependence emerges in both models when the excited level of TL-active trap is deep enough. The reported effect was demonstrated to be directly related to intracluster non-radiative recombination of electron at the excited level of the trap and hole in the luminescence center. The intracluster competition between hole centers makes dose response less non-monotonic. When the heating rate decreases, TL yield at high doses drops and TL dose dependence becomes more non-monotonic.