Changes in the absorption spectra, introduced by 60Co irradiation and high-temperature annealing, were studied. On the basis of the radiation and annealing-induced absorption spectra, 2 color centers were deduced to be responsible for shaping the absorption spectrum of crystals below 3.6eV. These were: Pb3+, O-, F and F+. Thermoluminescence glow curves were also studied above room temperature in order to determine the trap levels which resulted from irradiation.

M.Nikl, K.Nitsch, S.Baccaro, A.Cecilia, M.Montecchi, B.Borgia, I.Dafinei, M.Diemoz, M.Martini, E.Rosetta, G.Spinolo, A.Vedda, M.Kobayashi, M.Ishii, Y.Usuki, O.Jarolimek, P.Reiche: Journal of Applied Physics, 1997, 82[11], 5758-62