Effects of irradiation on transmittance of cerium doped germanate glasses in the ultraviolet and visible regions

A set of heavy germanate glasses were presented as the host for scintillating rare earths. The glasses consisted of GeO2, Gd2O3, BaO as the main constituents and Ce2O3 and Tb2O3 for introducing the activating cations Ce3+ and Tb3+. Ultraviolet and visible transmittance spectra were measured on glass samples before and after irradiations at different doses to study the effects of ionising radiation on their transmission properties. Irradiated samples were submitted to annealing treatments and their transmittance spectra were compared with respect to their thermal bleaching behaviours. Extraordinary irradiation resistance of Ce3+ doped glasses was observed after comparison with their counterparts doped with Tb3+, which is of special significance for their applications in high-energy particle experiments. Possible mechanisms causing the positive effect of cerium doping was discussed in terms of its special valence electron orbital configuration.