A novel ionizing radiation sensor utilizing radiophotoluminescence in silver-doped phosphate glass

Abstract

Silver (Ag + ) doped phosphate glass exhibits an intense photoluminescence (PL) when the non-irradiated Ag + -doped phosphate glass is excited with about 230 nm ultra-violet light. In x-ray irradiated glass, intense radiophotoluminescense (RPL) is observed when the irradiated glass is excited with about 340 nm ultra-violet light. It is found that the RPL spectrum includes two emission bands such as blue emission band peaked at about 460 nm (lifetime: about 6.6 ns) and yellow RPL emission band peaked at about 560 nm (lifetime : about 2.2μs). The PL intensity is decreased with increasing x-ray irradiation dose, while the RPL intensity is increased with x-ray absorbed dose. For the annealing of x-ray irradiated glass at 523 K, the RPL intensity is decreased with annealing, while the PL intensity is increased with annealing. The RPL is vanished and the PL is recovered at original intensity by annealing at 523 K for 40 min. This means that there is a complementary relationship between the PL and RPL on irradiation and heat-treatment processes. The RPL intensity is increased with increasing the x-ray absorbed dose in the range from 0.01 mGy to about 20 Gy, showing that the Ag + -doped phosphate glass can be useful for individual radiation monitoring and environmental radiation monitoring. On the basis of such potentiality of glass as the dosimeter, the application of Ag + -doped phosphate glass on environmental radiation monitoring is discussed and the RPL response of the glass for α- particle and heavy-particle (He, C, Fe particle) irradiation is demonstrated.