Formation of Color Centers in Glasses Exposed to Gamma Radiation

Abstract

Glasses exposed to gamma radiation develop a visible absorption band similar to the F‐band developed in alkali halide crystals. The function of cerium in preventing coloration of glass was studied in detail in an ultraviolet‐transmitting phosphate base glass in which its characteristic absorption could be measured. When visible absorption was thus prevented, radiation still caused a strong absorption in the ultraviolet which was associated with the electronic structure of cerium. On this basis, transition ions of similar electronic structure were introduced. It was found that iron, manganese, cobalt, nickel, vanadium, copper, and, under certain conditions, some other elements do suppress the formation of the visible absorption band formed in the base glass by radiation while forming more or less prominent bands in other spectral regions. Thus the colorless iron phosphate glass remained colorless under radiation and could be considered to be “protected.” Conversely, with cobalt the new band which reached into the visible was relatively intense and stable, suggesting its use to indicate radiation dose.