The positron annihilation lifetime spectra of unirradiated and gamma- ray irradiated thermoluminesecent materials LiF:Mg

Ti and LiF:Mg

Cu

P and MgSO4 have been decomposed into three components. The for the heavily doped LiF samples are very similar

which implies that the positive ion vacancies have less effect on the spectra. lt is observed that 2 alters slightly but oppositely with dose in a dose range from 0.05 to 1kGy. lsochronal annealing of the irradiated MgSO4 samples indicates that the and may be related to R radicals（where R represents SO42￣

SO4￣ and SO3￣ ）

and their intensities I and I3 are probably dependent on the formed （Mg2+ vacancy-R） complexes and their competition.