Comparative study on quantitative carbon content mapping in archaeological ferrous metals with laserinduced plasma spectroscopy (LIBS) and nuclear reaction analysis (NRA) for 3D representation by LIBS

The carbon content distribution of ferrous archaeological artefacts in a quantitative way allows us to understand the nature of the materials. Our previous works have ever proved that the use of laser-induced breakdown spectroscopy (LIBS) could be an efficient method to solve problems of in situ analysis and offer a high spatial resolution. To assess the ability of this quantification in an absolute way the carbon quantification by LIBS is compared in this paper with the nuclear reaction analysis (NRA), one of the ion beam analysis (IBA) techniques generated by a deuterium ion beam. The IBA analysis has specific advantages, especially in terms of precision and non-destructiveness. A validation study is also presented on quantitative carbon content mapping in archaeological ferrous metals with LIBS and deuterium ion beam analysis. The application of LIBS quantitative mapping on different structures of archaeological pieces shows that the carbon content distribution can be well determined, demonstrating the 2D mapping capabilities of the laser techniques. With the help of LIBS stratigraphic analysis, a 3D deeper insight on microscale features presents a heterogeneity, induced better understanding of material organization at the microscale.