Intercomparison exercise on electron paramagnetic resonance dosimetry in sorbitol.

This paper presents the results of the first intercomparison exercise on Electron Paramagnetic Resonance (EPR) dosimetry using sorbitol, where the performance parameters of sorbitol as dosimetric material were evaluated by three independent participants. Each participant was asked to determine a calibration curve using a set of sorbitol powder samples irradiated to four different doses (1.00, 2.50, 5.00, and 10.00 Gy of air kerma). The calibration doses were known to the participants, who were asked to measure each sample three times, and to report the EPR signal response, the mass of aliquots measured, and the parameters of EPR signal acquisition and signal evaluation. Critical dose and detection limit were calculated based on the calibration-curve parameters obtained by each participant. The mean values of the detection limit and average critical dose were found to be 802 ± 148 mGy and 411 ± 77 mGy, respectively. These values were compared with those of for alanine, glass and tooth enamel. The participants were also provided with four blind samples irradiated to four unknown doses, and their reported doses were compared with the delivered doses and performance quotient was calculated for each participant. The findings indicate that sorbitol is a promising candidate for accidental and retrospective dosimetry.