Effects of selected physical parameters on the gamma-ray-induced EPR signal of glycine dosimeter

Abstract

Electron paramagnetic resonance (EPR) dosimetric characteristics of glycine irradiated with a broad range of gamma doses, ranging from 0.1 Gy up to 100 kGy, were examined. Further physical parameters were investigated, such as irradiation temperature, dose fractionation, fading for different isothermal annealing temperatures, and UV exposure. The gamma dose response of glycine represents ~ 36% of that of alanine at a gamma dose of 5 kGy, and this ratio decreases as the gamma dose increases. The calculated detection limit is about 130 mGy. There is no significant variation in the EPR intensity of exposed glycine due to the change in the intermediate intervals between the two fractions. The optimum annealing temperature and duration time overcoming the fading impact for immediate readout of glycine after irradiation were found to be 110 °C for 15 min. UVC induces a broad peak in the unirradiated glycine sample at the same position that overlaps with the dosimetric peak of gamma rays. Keeping the glycine dosimeter in the dark is recommended to prevent the UV effect.