Radioluminescence Processes in Cerium-Doped Silica Glasses

Rare-earth (RE)-doped silica glasses are promising materials for ionizing radiation dosimetry. In this article, a bulk glassy silica doped with Ce ions was prepared via the sol-gel technique and drawn at about 2000 degrees C into a cylindrical capillary rod. Under X-rays, this sample presents a radioluminescence (RL) signal that can be exploited for dose rate real-time monitoring with remarkable linear response spanning six decimal orders of magnitude. In order to elucidate RL signal dynamics associated with free carriers trapping-detrapping and recombination during and after X-ray irradiation, we studied the obtained RL signals using a kinetic model involving one or several trapping states and one recombination center. With this model and using appropriate sets of trapping parameters, extracted from the thermoluminescence data, the RL signal was numerically simulated, along with the populations of the relevant traps and centers. Several experimentally observed characteristics of the RL signals were explained using the model.