High sensitive CaSO4:Dy TLD sintered pellets for applications in radiation protection dosimetry

This work reports the successful development of solid sintered pellets (weight = 60 mg, diameter = 6.mm and thickness = 0.9 mm) made from the high-sensitive CaSO4:Dy thermostimulated luminescence (TSL) phosphor synthesized recently along with suitable inorganic binders. The change in their weight was found to be negligible over 5 month storage in ambient climate which indicate their stability against humidity. In pellets the relative contribution of ∼ 100 deg C peak is slightly enhanced. Nevertheless in view of higher phosphor content, dosimetric (∼230 deg C) peak in pellets is 2 times more sensitive than that of Teflon discs. Since the pellets could be heated to temperatures up to 700 deg C, TSL could be read within a few seconds by heating them quickly to a high temperature. These as well as other dosimetric characteristics (such as detection threshold, dose versus TSL response, reusuability, light sensitivity, storage stability etc) of the pellets will be presented. Results obtained so far show that the characteristics of CaSO4:Dy pellet are far more superior to those of Teflon disc for applications in personnel and environmental monitoring