Thermal stability assessment of OSL signal by measuring the OSL thermal depletion curves

Abstract

Metastable states called traps in minerals are responsible for the optically stimulated luminescence (OSL) exploited in dating sediments and thermochronometry. The accuracy of trap parameters that determine the OSL thermal stability is crucial for the quality of results. A method of trap parameter determination used more and more often is the isothermal holding experiment. The problem that makes measurement results hard to interpret is the presence of other traps in the sample apart from the investigated one. Here, simulations of basic processes during isothermal holding experiments are made for a model including three traps. They prove that the irradiation dose and preheat impact the estimated trap parameters. In the presented results of experiments for quartz, which is a much more complex system than the considered model, one can recognize the characteristic effects observed in the simulations. The ways of recognizing the effects responsible for disturbances of results and improving measurements are indicated.