Synthesis and optimization of the composite pellets of SrS:Ce,Sm nano-phosphor as a sensor for the space radiation dosimeter

In this study, the SrS nanopowder co-activated by Ce3+ and Sm3+ (SrS:Ce,Sm) was synthesized by the co-precipitation method. The transparent pellets were fabricated by mixing the SrS:Ce,Sm nanopowder and bisphenol-A epoxy resin as a crystal of the optically stimulated luminescence (OSL) dosimeter. The crystalline phase verification and also, the morphology of the synthesized nanopowder were investigated using the XRD patterns and FESEM images, respectively. The effects of Ce3+ and Sm3+ concentration and the Thioglycerol (as capping agent) concentration on the sensitivity of SrS:Ce,Sm OSL response were evaluated in the same exposure and measurement conditions. The obtained results demonstrated the optimum sensitivity of the OSL response of the samples to a test dose of approximately 0.4 mGy by X-ray irradiation, which was related to 0.02 and 0.01 mol% concentrations of Ce and Sm, respectively; the 0.1 M concentration of the Thioglycerol was associated with the nanocrystallite size of 24+2 nm as well.