Stability study of free radicals in 10 MeV electron beam irradiated quartz as an EPR dosimetry method

In this work the stability of free radicals induced by a 10 MeV electron beam in quartz samples was studied. The investigations have been done for different doses and different dose rates. For this reason, quartz samples in powder form were irradiated at different dose rates, i.e. 100, 260 and 630 kGy/min for absorbed dose range of ~ 5-80 kGy using the 10 MeV electron beam radiation. The dose values were validated using a polystyrene calorim- eter system as a reference standard dosimetry system. The EPR optimum system parameters were defined and EPR responses at room temperature in air were measured and compared. The EPR signal, which is due to the free radicals induced by electron beam, was also investigated at different time intervals to check its stability. The main objective of this work was to study the feasibility of using quartz as a dosimeter. Thus, the variation of EPR signal intensities with the absorbed dose values were evaluated and plotted in a graph. The results show that the variation of dose rate, do not affect considerably the EPR response.