An improved experimental setup for the simultaneous PIXE analysis of heavy and light elements with a 3 MeV proton external beam

The external beam line of the AGLAE IBA facility at the Laboratoire de Recherche des Musees de France is of particular relevance for the analysis of works of art and archaeological artefacts. In order to reduce both target damage and acquisition time, we perform the simultaneous analysis of light (5 < Z < 30) and heavy elements by PIXE with 3 MeV protons, using two Si(Li) X-ray detectors. To achieve this goal, we have made the following improvements to the experimental setup. (i) To protect the low energy dedicated Si(Li) crystal from the backscattered protons which could markedly alter its resolution, a compact magnetic deflector has been designed and placed along the outgoing X-ray path. (ii) The ultrathin detector window is shielded against visible light by a 100 mu g/cm(2) carbon foil. (iii) To reduce the angular straggling of the backscattered particles and to keep a good X-ray transmission for elements down to carbon, the whole system is flooded with He or H gas. In this paper, we present different tests and preliminary results obtained with this setup.