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

Abstract

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 (De) 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 De. 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 De 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 De determination. Relevant mechanisms are explained, and implications on dose measurements using the SAR protocol are discussed.