Tooth enamel EPR dosimetry: sources of errors and their correction

Some of the most important sources of systematic errors in dose determinati on using tooth enamel EPR spectroscopy and ways of reducing those errors ar e discussed. Enamel from the outside of the front teeth should not be used for dose determination because of induction of paramagnetic centers by sola r light. The accuracy of the method in the low dose range is limited by var iation in the shape of the EPR signal of unirradiated enamel, which can be described by an initial intrinsic signal and which varies for different sam ples with standard deviation of 20-30 mGy. The energy dependence of enamel sensitivity should be taken into account in the form of a correction factor . The value of this factor is estimated at 1.1-1.3 for real radiation field s in radiation contaminated territories. Variation in enamel sensitivity fo r different samples is shown to be within limits of 10-15% of the average v alue. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.