Gamma-Ray-Induced Coloration in Solids; Application to Glass Systems

General aspects of radiation-induced coloration in solids are discussed. It is considered that the most significant initial effect of the radiation is to produce free electrons and trapped holes in a track. The decay of the track from the initial condition is described in some detail, assuming (a) that the rate of diffusion of electrons from the track is small compared with the rates of other processes and (b) that primary processes which form color centers can be considered to be independent of secondary processes which cause destruction of color centers. A method of calculation is described which gives the concentration of color centers formed at various doses. With plausible assumptions for the parameters, agreement with the data of Schulman et al. on a silver phosphate glass is obtained. The treatment of glasses less simple than the silver phosphate glass is also discussed.