Thermal glow peaks in KC1: Tl around room temperature

Abstract

Thermal glow curves of KC1 : Tl have been recorded in the ultra-violet and visible regions after irradiation with ultra-violet light at room temperature. Two broad but well-defined peaks at 300 and 350°K are observed in the range from room temperature up to 450°K. The work includes the effects on the thermoluminescent characteristics of the phosphor when subjected to various thermal treatments. It is suggested that (a) the dislocations operate as effective agents in bringing about the trap distribution changes after thermal treatment and (b) the glow peak at 350°K is complex in nature formed by the merging of closely spaced peaks. The thermoluminescence is supposed to arise from the recombination of electrons trapped at negative ion vacancies in different environments and holes at Tl centres.