Dosimetry based on thermally and optically stimulated luminescence

Abstract

Thermally Stimulated Luminescence (TL) and Optically Stimulated Luminescence (OSL) properties of quartz and a -Al₂O₃ have been investigated. Anneling-induced OSL and TL sensitivity changes in quartz has been investigated by experiments and modelling.
This study does not support a pre-dose effect to account for the observed annealing-induced sensitivity change. The experimental data indicates a more simple mechanism that involves alteration of the concentration of the defect centers. Results from modelling of removal or creation of defect centers comparing well with experimentally obtained data.

Thermal quenching of luminescence for the main emission center, the F-center, in a -Al₂O₃:C has been investigated by analysing TL curves obtained at different heating rates. The thermal quenching dependence of luminescence is found to follow the classical Mott-Seitz expression. Basic investigations of OSL properties of a  Al₂O₃:C, including: the thermal depth of the OSL traps, the temperature dependence of OSL, and the OSL stimulation spectra.
Simultaneous measurements of TL and thermally stimulated conductivity (TSC) are presented for gamma-irradiated a  Al₂O₃:C.
 Activation energy analysis of the data reveals a superposition of several first-order TL and TSC peaks caused by release of charge carriers from a distribution of trapping states. Furthermore a description of an experimental method developed to determine the sign of the thermally released charge carriers has been presented.