Doping of CaSO4 for development as a luminescence dosimeter and study of its characteristics

Calcium sulfate (CaSO4) is a well-known phosphor and has also been recognized as a useful TL material in radiation dosimetry. However, apart from its chemical, structural and thermal luminescence properties, not too many publications have been reported in the literature on the properties of OSL, particularly the activation energies of CaSO4 phosphors. Therefore, in this study, a sample of Eu- and Tb doped calcium sulfate was synthesized using the precipitation method to create new traps and recombination centers, and the properties of OSL were examined for applicability in radiation dosimetry. It was analyzed by XRD and SEM to ensure that it was successfully synthesized and to get an idea of the crystallography and microstructure morphology of the material. In addition, FT-IR analysis was used to observe the vibrational modes of the functional groups of the produced phases and DSC and TG analyzes were used to investigate the chemical and physical changes in the material during temperature measurement. To obtain OSL signals and to investigate the dosimetric properties of cold-pressed Eu- and Tb-doped CaSO4 pellets, the Risø TL/OSL reader model DA-20 was used. The samples were exposed to the beta particles using the (90Sr/90Y) beta source equipped with this instrument. In addition to examining dosimetric properties such as dose-response, reusability and fading properties, the effects of minimum detectable dose, thermal stability and reading temperature were also investigated and activation energies were determined. This study shows that the dosimetric properties of CaSO4:Tb, Eu pellets are adequate for dosimetry and this material could be used widely in the future if it will be developed for dosimetric purposes.