Characterization of the Effect of ɤ-Radiation Absorbed Dose on the Electrical Conductivity of Aqueous Urea Solutions in the Presence of Silica Gel :A Preliminary Dosimetric Study

Abstract

ɤ-radiolysis of 6M-aqueous urea solutions, in the presence of silica gel (SG) significantly increases the values of electrical conductivity (RIC) of the solutions, relative to that in the absence of SG. Some dosimetric characteristics were studied, such as the effects of the absorbed dose, absorbed dose rate, and post-irradiation storage time on the RIC of the irradiated 6M-aqueous urea solutions in the presence of SG (>0.16mm-0.2mm). A linear relationship between the RIC of the solutions and the absorbed dose (R 2 = 0.998) was observed from 0.240 to 17.670 kGy. The uncertainty in the dose-response function was found to be in the range 0.040-0.320 at 95% confidence level. As the dose rate increases, the RICdecreases in the range of 0.298-1.19 kGy/h. The stability of the response (RIC) of the irradiated solutions is acceptable during post irradiation storage (14 days at 0 o C) where the response (RIC) decreased at the end of the storage period, 0.49-2.8%%. The effective atomic number of this solution (7.08) was found to be compatible with biological tissues. The results show that the studied system can be considered a promising dosimeter for low dose applications in the range 0.240 to 17.670 kGy, such as medicine and food irradiation.