Radiation-induced electron transfer and the protective effect of cerium in radiation-resistant glasses

The characteristics of radiation processes in K8 and K108 industrial glasses and in model glasses of the composition (mole %): 22Na2O·3CaO·75SiO2 with CeO2 additives and for several glasses with Fe2O3 were investigated in the study. The purpose of these studies was to establish the mechanism of the protective effect of Ce3+ and determine the quantitative characteristics of these processes. The absorption spectra of the glasses before and after irradiation with UV light and/or y-quanta were analyzed and the concentration curves were obtained for the intrinsic hole color centers as a function of the concentration of Fe3+ in series of glasses with and without Fe3+ ion additives - effective impurity electron acceptors. Evidence was obtained which indicated that radiation-stimulated ionization of Ce3+ with electron transfer to intrinsic hole color centers, and not capture of holes by Ce3+ ions (as hypothesized previously) could be the basis of the protective effect of Ce3+ which decreases the concentration of intrinsic hole color centers responsible for radiation coloration of glasses. The limiting concentrations of color centers in K8 and K108 glasses were established, the radiation yield of color centers in conversion to one absorbed y-quantum or 100 eV of primary radiation energy was determined, and the degree of recharge of Ce3+ was found for different doses and types of radiation