Thermoluminescence behaviour of KCL(1-x)Br(x):Pb2+ exposed to gamma radiation.

The thermoluminescence (TL) behaviour of solid solutions of lead doped KCl(1-x)Br(x) (X = 0.02, 0.35, 0.50, 0.65, 0.85, 1) mixed crystals exposed to gamma radiation at different doses from 60Co is reported. The TL glow curves of KCl(1-x)Br(x):Pb2+ crystal exposed in the range of 0-140 Gy is strongly dependent on composition X. The maximum temperature of the main TL glow peak was found to shift towards lower temperatures as composition X increased and a significant enhancement of the TL efficiency in KCl(1-x)Br(x):Pb2+ was found for X = 0.50 which is attributed to an increase in the vacancy concentration of the mixed halides at middle composition. The participation of the F-centre in the TL phenomenon particularly related to the main TL glow peak observed in mixed samples was also confirmed.