External proton beam analysis of layered objects

Ion-beam analysis for determining the elemental composition and to obtain depth information has been carried out with MeV protons in air by means of simultaneous external PIXE and RBS. Stainless steel products of extended size and a historic painting are analysed non-destructively. These objects include systems of layers with area densities up to some mg/cm². Depth information is obtained by PIXE using energy variation of the primary proton beam and in addition directly from RBS for the outermost near-surface region. Main and secondary elements as well as impurities can be determined together with area densities. Particularly, the knowledge on the depth distribution of the pigments in paintings provides information on paint techniques.