Studies of thermal stability of charges associated with thermal transfer of OSL from quartz

Abstract

In this paper we study optically stimulated luminescence (OSL) signals created by basic thermal transfer. The thermal stabilities of trapped charges associated with the source traps of thermal transfer and their related OSL traps, and trapped holes associated with non-luminescent centres (R centres) were studied for a sedimentary quartz, using isothermal annealing and pulse annealing methods. The thermally transferred charges are mainly from three groups of traps (source traps), shallow, medium and deep traps. Kinetic analysis indicates that the medium and deep source traps have trap depths of ∼1.1 eV and ∼1.5 eV, and lifetimes 7.6 × 105 and 6.0 × 1011 years at 20 °C, respectively. Two kinds of OSL traps, one unstable and the other stable, are identified as accepting charges during thermal transfer. These OSL traps have different thermal stabilities from the main OSL traps, which are associated with the 325 °C TL peak. The results also indicate that the basic thermal transfer related OSL signals perhaps use different R centres from the dose-generated fast bleachable OSL signals. © 2006 IOP Publishing Ltd.