Some aspects of phenomenology and kinetics of high temperature thermoluminescence of plagioclase feldspars

Plagioclase feldspars generally display a bright UV TL emission at high temperature (ca 600∘C). When preheating procedures are used, this TL peak has a very reproducible shape and can be fitted by a single glow-curve with close to second-order kinetics. Nevertheless other experimental evidence, such as the growth of TL intensity with radiation dose or phosphorescence experiments, contradict this simple model. Simulation of experimental data and best-fit techniques indicate that a bell shape model for trap depth distribution is better compatible with the observed data. Furthermore, such a trap distribution model explains some aspects of the behaviour of TL at the onset of saturation. Values of frequency factors and trap depths imply thermal stability for the trapped electrons responsible for high temperature TL.