A ceric-cerous sulfate dosimeter

With a spectrophotometer at wavelength of 320 nm, the molar linear absorption coefficient determined for Ce4+ ions in acidic sulfate solution is 599.1 m2/mol and its linearity is better than 0.5% in the absorption range from 0.1 to 1.6. The repeatability of the background readings for dosimeters is better than 1%. The G value of Ce3+ ions of the system is 2.39 x 10-7 mol/J(+-1.2%), and the dose conversion factor K is 724.8 Gy. From the experiment, it is found that G value will decrease 0.25% if the temperature rises 1 degree C. The measuring range for the dosimeter is from 4 to 35 kGy and the total uncertainty is 4% (95% confidence). The post-irradiation experiments of the dosimeters have been carried out. If dosimeters are kept from sunlight, they are stable in 34 days after irradiation. It is shown that the ceric-cerous sulfate can work as transfer dosimeter or standard dosimeter for measurement