Enamel dose calculation by electron paramagnetic resonance spectral simulation technique / 中华放射医学与防护杂志

ABSTRACT

Objective To optimize the enamel electron paramagnetic resonance (EPR) spectral processing by using the EPR spectral simulation method to improve the accuracy of enamel EPR dosimetry and reduce artificial error.Methods The multi-component superimposed EPR powder spectral simulation software was developed to simulate EPR spectrum models of the background signal(BS) and the radiation- induced signal (RS) of irradiated enamel respectively.RS was extracted from the multi-component superimposed spectrum of irradiated enamel and its amplitude was calculated.The dose-response curve was then established for calculating the doses of a group of enamel samples.The result of estimated dose was compared with that calculated by traditional method.Results BS was simulated as a powder spectrum of gaussian line shape with the following spectrum parametersg =2.00 35 and Hpp =0.65 - 1.1 mT,RS signal was also simulated as a powder spectrum but with axi-symmetric spectrum characteristics.The spectrum parameters of RS wereg(1) =2.0018,g (11) =1.996 5,Hpp =0.335 - 0.4 mT.The amplitude of RS had a linear response to radiation dose with the regression equation as y =240.74x + 76 724 ( R2 =0.9947 ).The expectation of relative error of dose estimation was 0.13.Conclusions EPR simulation method has improved somehow the accuracy and reliability of enamel EPR dose estimation.