Quantification of sodium in ancient Roman glasses with ion beam analysis

Concentrations of light elements (Na, Al, Si) in glass have been profiled by comparing the PIGE yields as a function of beam energy to those of a glass standard in combination with PIXE measurements which are used to determine the specific energy loss of protons in the unknown glasses. The technique has been tested on a known sample and applied to a few Roman natron glasses giving results compatible with the morphology of the archaeological samples, as deduced from microscopy. The results have suggested some considerations on the systematic use of the PIGE technique in the determination of bulk sodium concentration in ancient materials.