Tl Glow Curve and Effect of Annealing Analysis on Natural Barite Collected from Mangampeta, India

The thermostimulated luminescence (TSL) glow curve characteristics of ten barite crystals of Mangampeta mines (Cuddapah District of Andhra Pradesh, India) were analysed. The natural thermoluminescence (NTL) measurements were carried out for all the samples and show three peaks at 80oC, 120oC and 295C, when recorded with linear heating rate of 10°C/sec. The sample irradiated with a gamma dose of 100 Gy shows a new peak at 215C with NTL observation, but the absence of 295C glow peak. The annealed sample also shows the same trend. The sample was annealed in air at the temperatures ranging from 200C to 1000C, at an interval of 50C, for 1 hr duration. Annealing treatment above 400C increases the sensitivity of 215C TSL peak but there is no change in other two peaks. On the other hand, annealing at 800C caused a complete removal of low temperature peaks (80oC and 120oC). The enhancement in TSL sensitivity was found to depend on the annealing temperature. The optimum annealing temperature was fixed for getting maximum TL sensitivity.