The dependence of radiophotoluminescence (RPL) and photoluminescence (PL) properties on x-ray irradiation dose and heat-treatment after irradiation was investigated for Ag⁺-activated phosphate glass, which is practically used as glass dosimeter for individual monitoring of ionizing radiation. The RPL intensity was increased with increasing x-ray irradiation dose, while the PL intensity was oppositely decreased with x-ray dose. The glass exhibited the vice versa tendency between the PL and RPL changes for heat-treatment at 250°C after x-ray irradiation, that is, the PL intensity was increased with annealing time, while RPL was decreased with annealing time. These results strongly support that the luminescence center of the PL is Ag⁺ and the centers of yellow RPL and blue RPL are Ag²⁺ and Ag⁰, respectively, which has been proposed in previous report. In addition, annealing temperature at 250°C for 40 min made it possible to save much energy and time required for recovering the used glass dosimeter to initial condition before x-ray irradiation.
It was also found from the dose dependence of the RPL intensity that the RPL intensity was saturated around higher dose region than about 15Gy, which means that there is no linearity between RPL intensity and radiation dose in high dose region.