A study based on ESR, XRD and SEM of signal induced by gamma irradiation in eggshell

ESR (electron spin resonance), XRD (X-ray diffraction) patterns and SEM (scanning electron microscopy) of irradiated calcium carbonate (CaCO3)(CaCO3) in eggshell was investigated. The ionizing radiation produces an electron centre CO33-, a hole centre CO3-, and the CO2- molecular ion also formed. The ESR centre with g//=1.9977g//=1.9977 and g⊥=2.0021g⊥=2.0021 was identified as the same found in hydroxyapatite. The work aims to standardize the samples preparation method and the conditions of measured for practical application by the specialist in emergency dosimetry. In this regard, practical consideration of sample preparation conditions and properties such as grain size, ESR spectra, and the temperature dependence of the signal were studied in detail. Dose response appears to be linear between 3 Gy and 1 kGy. No dose rate dependence was observed. The morphology of the calcined eggshell presented extensive morphological change on the calcinations process. Careful analyses of the ESR spectra are presently in progress in order to undertake and identify the radicals involved.