Combined theoretical and experimental study of luminescence in Gd³⁺ -doped silica glass under ionizing radiation

In the ionizing radiation dosimetry domain, there is still an important demand for a compact, reliable, and accurate sensor. Currently, among the dosimeters based on optical techniques, the fibered systems are the most promising solutions. Optical dosimeters usually exploit one of the physical processes, which is radioluminescence (RL), thermoluminescence (TL) or radiation-induced attenuation (RIA). In this paper, we present, to our knowledge, a new approach to measuring the dose of ionizing radiations that combines radioluminescence, phosphorescence, and thermoluminescence processes. To our knowledge, the integrated signals originating from these three processes have been collected at different temperatures through an optical fiber spliced to a Gd³⁺-doped silica glass rod for the first time. Using this fibered setup, the experimental study shows that the integrated response, originating from the three processes, is linear versus dose at least up to 300 Gy and temperature-independent between 153 K and 353 K. These experimental results have been explained and reproduced by a theoretical model, which is also able to predict the dosimeter response under various conditions. Moreover, as another novelty, to our knowledge, simultaneous optically stimulated luminescence (OSL) and RL measurements allowed the achievement of a real-time and temperature-independent dosimeter.