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

The optically stimulated luminescence (OSL) from quartz relates to not only the trapped electrons associated with the OSL signals, but also the luminescence centres involved. In this paper we report pulse annealing and isothermal annealing experiments on a 17 ka old sedimentary quartz to study thermal stability of electrons in OSL traps and the trapped holes associated with the non-luminescence centres (R centres). The lifetimes obtained are in the order of magnitude of 10⁹ and 10⁴ years at 20 °C, for electrons in the stable OSL traps and the holes associated with sensitivity change, respectively. The results indicate that the OSL sensitivity change is dominated by the transferring of holes from one type of R centre to luminescence centres (L centres), and is different from the 110 °C TL peak, which appears to involve more than one type of R hole centre.