Optical and thermal pre-readout treatments to reduce the influence of fading on LiMgPO4 OSL measurements

Abstract

TL (Thermoluminescent) and OSL (Optically Stimulated Luminescence) techniques are both luminescent techniques widely applied in several areas into radiation dosimetry. The main difference between them are related to the employed stimulus (thermal or optical) for luminescent emission, as well as the advantages of each technique. Due to simplicity and not to be required heating, the OSL technique has been continuously improved and new researches in materials to be used with this technique have grown in the last decades. Nowadays the main problems in the application of the developed new materials are the poor stability and loss of OSL signal over time (fading). In this study, we performed a sequence of thermal (preheat) and optical (OSL with infra-red light stimulus) pre-readout treatments immediately before OSL readouts of LiMgPO4 based detectors (LMP), aiming the applicability of novel materials, contributing to find solutions to minimize the influence of fading. Moreover, it was demonstrated that the influence of fading is minimized and the stability of OSL signal from LMP is achieved using just optical process, without heating the material.