PIXE facility at Centro Atómico Bariloche.

Abstract: A 1.7MeV tandem accelerator has been recently installed at Centro Atómico Bariloche, Argentina. This communication includes a brief description of the system facility with the main associated equipment, in particular that used for PIXE measurements. The X-ray detector efficiency was experimentally determined by comparing X-ray characteristic spectra with theoretical predictions. The knowledge of this parameter allows us to perform quantification without standards with good precision. We show some recent applications of PIXE in archaeology and forensic science done at our laboratory. In the archaeological field we determined elements constituent of pastes and black, white, brown and ocher pigments from Aguada Portezuelo Culture (600–900 AD). This study allowed us to infer about the presence of psilomelante mineral (a mineral with barium) as precursor of some black pigments. In the forensic field we determined trace elements that are present in seven gunpowders commonly used in Argentina. We note that any gunpowder can be distinguished by the presence of trace elements. [Copyright &y& Elsevier]