Modelling the dependence of equivalent dose determined from a dose recovery test on preheating temperature: The intervention of shallow electron traps

In optically stimulated luminescence (OSL) dating, the performance of the single-aliquot regenerative-dose (SAR) protocol is commonly tested using a dose recovery test. The dependence of equivalent dose (D_e) determined in a dose recovery test on preheating temperature using quartz OSL was reported in previous studies which demonstrated that using a lower preheating temperature prior to the measurement of the test dose OSL response may result in serious underestimation of the recovered D_e. In this study, we simulate the variation of normalised sensitivity-corrected OSL signals as a function of cycle number and the dependence of the recovered D_e on preheating conditions, using a kinetic model consisting of four electron traps and two recombination centres. Experimentally observed phenomena are successfully reproduced using the model with a set of optimised kinetic parameters. We suggest that the intervention of shallow electron traps may play a significant role in affecting the accuracy of D_e determination. Relevant mechanisms are explained, and implications on dose measurements using the SAR protocol are discussed.