Induced optical absorption of silicate glasses due to gamma irradiation at high temperatures

Gamma radiation-induced optical absorption in 75SiO2-22Na2O-3CaO (wt.%) multi-component glass and in the same glass additionally doped with 0.05 wt.% CeO2 has been studied, with irradiations performed at 70, 200, and 350 deg. C, 25 kGy/h up to a dose of 0.6 MGy. For the undoped glass irradiation at 70 deg. C produces strong optical absorption from 700 nm down to the UV. Irradiation at 200 deg. C gives a lower level of optical absorption with a similar band composition. No induced optical absorption has been detected after irradiation at 350 deg. C. Annealing at 200 deg. C for 24 h completely suppresses the induced optical absorption. Introduction of cerium increases the level of induced absorption in the UV range for irradiation at 70 deg. C, and also creates bands stable up to 350 deg. C. The results show that silica and sapphire, which are considered as main candidate materials for ITER diagnostic windows and other optical components, can potentially be complemented with multi-component silicate glasses. These materials may allow one to control the radioluminescence, and in addition provide a range of refractive indices required for achromatic lenses.