Electron Spin Resonance and Thermoluminescence Dosimetry of Clear Fused Quartz: Its Possible Use for Personal, High Dose and High Temperature Dosimetry

The thermoluminescence (TL) properties and electron spin resonance (ESR) response of clear fused quartz (CFQ) have been studied. Small cylindrical samples of CFQ were exposed to a range of doses from a 60Co source and then subjected to TL readout or ESR measurement. It was found that the minimum detectable dose (i.e. the dose which corresponds to twice the standard deviation of the background signal) is about 40 µGy for TL and about 1 Gy for ESR (three scans being accumulated at room temperature). The TL response of the samples exhibits good linearity at doses of up to 250 Gy, above which the signal rapidly saturates. The ESR response is linear up to a dose of about 200 Gy and sub-linear up to the largest evaluated dose of 3 x 104 Gy. Annealing studies have shown that the TL signal is reduced by more than two orders of magnitude following heating at 300 oC for 20 min. At this temperature the ESR signal is reduced by only about 30% and remains measurable following annealing temperatures in excess of about 600 oC. These results for CFQ suggest that TL can be used for personal dosimetry and ESR for high dose and high temperature dosimetry.