Non-destructive analysis of coins using high-energy PIXE

At the Ionenstrahllabor (ion beam laboratory) a great variety of ions with variable energies up to several MeV/u can be produced. Performing proton induced X-ray emission (PIXE) with protons of 68 MeV, heavy elements can be detected via the K X-rays in addition to their L X-rays. The large proton range and the small absorption coefficients for the K X-rays result in an analysable depth of several millimeters. The L-K line intensity ratio yields further information on the composition of the objects. The objects of the study were so-called "Wiener Pfennige" found in Tulln, Austria. The "hoard of Tulln" contains about 11000 of these silver coins which were strongly corroded and agglomerated to a single block. After the restoration non-destructive analysis should provide information about the elemental composition. The goal was to show the evolution of the copper content of the coins and the verification of the actual coin classification. (C) 2004 Elsevier B.V. All rights reserved.