Thermoluminescence characterization of nanocrystalline powder of SrSO4:Sm exposed to gamma radiation for dosimetric applications.

Dosimetry properties of nanocrystalline SrSO4:Sm powders prepared via a co-participation method, were studied. X-ray diffraction, energy dispersive X-ray spectroscopy and Field emission scanning electron microscopy (FE-SEM) were used to investigate the structure, composition and morphology of nanocrystalline SrSO4:Sm powders. The nanocrystalline SrSO4:Sm powders had the orthorhombic crystal structure. FE-SEM image showed polygonal structure of particles with an average size of particles 0.2 μm. The thermoluminescence (TL) measurements for different concentration of samarium were done after gamma irradiation. TL glow curves showed the main glow peak at 370 °C. The maximum intensity of the TL glow curves for SrSO4:Sm was obtained with 0.05mol% concentration of Sm. Then, due to its high intensity glow curve, it was selected as the main sample. Furthermore, its dose-response, energy-response, and fading were studied in detail. Nanocrystalline SrSO4:Sm(0.05 mol%) powder had a linear dose-response approximately between 10Gy and 3 kGy. It showed energy dependence for low energy photons and its fading was less than 20% after 37 days. The X-ray excited luminescence (XEL), and TL were examined. The kinetic parameters were calculated by using the various TL analysis methods and OriginPro 8 software. The results showed the main TL glow peak obeyed second order kinetics.