CaSO4:Dy microphosphor for thermal neutron dosimetry

Dysprosium-doped calcium sulphate (CaSO4:Dy) microphosphor was synthesized by acid re-crystallization method and its thermoluminescence (TL) properties irradiated with thermal neutrons was studied. Structural and morphological characteristics have been studied using X-ray diffraction and SEM which mainly exhibits a orthorhombic structure with particle size of 200 to 250 µm. Moreover, thermal neutron dosimetric characteristics of the microphosphor such as thermoluminescence glow curve, TL dose-response have been studied. This microphosphor powder represents a TL glow peak (Tmax) centered at around 240 °C. The TL response of CaSO4:Dy microphosphor as a function of thermal neutron fluence is observed to be very linear upto the fluence of 52×1011 n/cm2 and further saturates. In addition, TL glow curves were deconvoluted by computerized glow curve deconvolution (CGCD) method and corresponding trapping parameters have been determined. It has been found that for every deconvoluted peak there is change in the order of kinetics. Overall, the experimental results show that the CaSO4:Dy microphosphor can have potential to be an effective thermal neutron dosimetry.