Signal processing for radiation dosimetry using EPR in dental enamel: comparison of three methods

We are reporting an alternative method of extracting useful dose informatio n from complex EPR spectra of dental enamel. Digital differentiation of the initial first derivative spectrum followed by filtering is used to clearly distinguish the radiation-induced signal from the native background signal . The peak-to-peak height of the resulting second derivative of the signal is then measured as an indication of absorbed dose. This method does not re quire preliminary elimination of the native background signal, and is not e ffected by any uncertainty in the determination of the background signal or by errors resulting from the subtraction of two signals of comparable magn itude. Ten enamel samples were irradiated with known doses in the range of 250-10(5) mGy. There was agreement for all the samples, within the typical experimental error of +/-10% for EPR dosimetry in dental enamel, between th e doses determined by two common techniques using native signal subtraction and the doses determined by the new second derivative method proposed here . (C) 2000 Elsevier Science Ltd. All rights reserved.