The UV-visible spectra of undoped and nominally transition metals (Ti>Cu) doped lead borate glasses have been measured from 200 to 1000nm before and after various doses of gamma-ray irradiation. In the undoped lead borate glass, strong charge transfer ultraviolet absorption bands are observed which are related to trace iron impurities and the possible sharing of Pb2+ ions. In transition metal (TM) doped glasses, characteristic absorption bands are recorded due to each specific TM ion which may interfere with that due to iron impurities. Gamma irradiation reveals significant changes depending on the TM ion and some of the ions show retardation effect as observed in the induced bands. The rates of formation or growth behaviour of the various induced defects are believed to approach saturation with prolonged irradiation.
