Defect clusters and thermoluminescence in LiF crystals

The thermoluminescence of pure and doped LiF crystals has been measured fol lowing irradiation at ambient temperature with gamma and x rays. Factors in vestigated include the effects of dopants (Mg, Mg/ Ti, and Fe) and of dose. Results are compared with optical absorption and photoluminescence measure ments made previously on the same crystals. The role of F, F-3(+), Z(2), an d colloids in the emission process is discussed. Some new effects are repor ted including step-like features in the glow curves at large doses. These a re explained in terms of the clustering of interstitial defects formed duri ng radiolysis. (C) 1999 American Institute of Physics. [S0021-8979(99)01315 -8].