Thermoluminescence of x- or γ-irradiated KI and KI(Ca2+) crystals

The thermal glow peaks obtained in undoped KI and KI:Ca2+, when they are x- or γ-irradiated in the temperature range 100-300 K, arise from the recombination of isolated F centres and the products of decomposition of either polyiodide ions or I2 crystalline aggregates induced by the ionising radiations. The structure of the traps of interstitial atoms was determined by Raman light scattering studies. All the results confirm that the emission of light involves recombination of F centres and the transient interstitials released from their traps, probably located near the F centres in the case of KI:Ca2+. No direct recombination occurs between interstitial atoms and potassium colloids, but it does occur via the evaporated F centres from the colloids. (author)