Repeated regeneration of thermoluminescence in γ-irradiated crystals

The two component room temperature thermoluminescence (RTL) from γ-irradiated crystals is attributed to such electrons as get stuck up at varying distances from holes, some within, and others outside the Onsager radius. The former recombine with holes fast, following first order kinetics, while the electrons lying farther away do so more slowly, following a pseudo-first order rate law. Side by side, the conduction-valence band gap is continually lowered to about 4 eV in the defect region by the clustering of interstitials around F centres. Resulting recombination TL is in the continuum, consistent with this model. Repeated regeneration of thermoluminescence (RRTL) induced by F light is due to the release of electrons from F centres. Once the F centres are completely bleached RRTL would cease. (author)