XRF analysis of art and archaeological objects with a charged particle accelerator

Both XRF and PIXE are of current use for the analysis of materials relevant to cultural heritage due to their good analytical capability and their non.destructive character. However they have own limitation in terms of sometimes high detection limit. For example, conventional XRF exhibits a strong background produced by the Bremsstrahlung radiation of incident electrons whereas PIXE is not appropriate for the analysis of light impurities in materials of high atomic number due to the intense emission of X-rays from the matrix. A solution for solving such draw backs is to transform the charged particle accelerator used for PIXE into an X-ray tube, by placing under the proton beam an intermediate target properly chosen to produce primary X-rays which then induce fluorescence on the sample under investigation. The primary X-ray beam is almost monochromatic (Ka and Kb lines with no Bremsstrahlung) and can been developed depending on the materials to analyse. They are all based on an external primary beam of protons hitting a primary target of a pure element (Ge, As, Zr, etc) Several issues of art or Archaeological significance have been addressed which show the advantages of such a methodology in comparison to more classical ones. They include the analysis of metal in mummies hairs of light impurities in papal lead seals and of trace elements in gold items