Electron paramagnetic resonance dosimetric response of Li2SO4 : CaSO4 mixture in mixed radiation environment - a case study

A new Electron Paramagnetic Resonance (EPR) dosimetry system based on the EPR response of 2:1 mixture of Li2SO4: CaSO4 is presented. The dose response of the material irradiated with 60Co gamma radiation was found to be linear in the range 3 Gy to 52 kGy having signal repeatability within ± 1 %. The dose response of the material irradiated in a mixed field of neutron flux of 3 x 1012 n-cm-2s-l also showed linearity in response for 5 minute to 45 minutes of irradiation. Some of the EPR signal parameters investigated include: peak to peak signal intensity vs neutron fluence, Δt = 5 min to 60 min, peak to peak signal intensity vs microwave power. Signal fading and repeatability, batch homogeneity and zero dose response. (author)