Analysis of the internal structure of ancient copper coins by neutron tomography

Abstract

The internal structure of copper coins—a Golden Horde pulo of the 14th century AD and an ancient coin found in Phanagoria at sites of the 5–4th centuries BC—are studied by neutron tomography method. From a set of angular projections of neutron absorption, three-dimensional models of the analyzed objects are reconstructed and the analysis of their physical state is performed. In the copper pulo, a region characterized by a greater neutron beam attenuation coefficient is found. It is assumed that this region was formed due to the gradual penetration of patina into the coin. The neutron tomography data also make it possible to analyze the remnants of an antique coin found in underwater archeological studies. Areas of surface damage and cracks in the antique coin are shown, visually separated from the corrosion layer.