Investigation of the electron paramagnetic resonance signal response in gamma-irradiated poly(lactic acid) for high-dose dosimetry

This paper is concerned with the investigation of the Electron Paramagnetic Resonance (EPR) signal response to Co-60 gamma ray radiation on poly(L-lactic acid) (Pla). The aim of this study is to assess the usefulness of Pla as a high-dose dosimeter. The EPR-signal response of Pla has been investigated to determine some of its dosimetric characteristics such as: signal intensity versus gamma dose received, zero-dose response, signal fading, signal repeatability, batch homogeneity, detection threshold,and stability under simulated sunlight exposure. It is concluded that Pla might be used as a high-dose dosimeter (10-500 kGy), with a very good reproducibility although its signal fading is about 9% in the first 5 hr. (author)