Defects States Induced by UV-Laser Irradiation in Scintillating Glasses

Emission intensity variation of the leading 542 nm emission line of Tb3+ centre in Na-Gd phosphate glasses under 308 nm excimer laser line irradiation was studied. Furthermore, induced optical absorption measurements after 308 nm laser, x-ray and gamma-ray irradiations were performed. Thermoluminescence above room temperature was also studied after 308 nm and x-ray irradiations at 295 K. The observed phenomenology evidences the presence of traps, which compete for carrier capture from the Gd3+ energy guiding sublattice with Tb3+ emission centres. The radiation induced optical absorption features are explained as due to both Tb4+ and host lattice-related hole colour centres.