Abstract: Trace elements in textile fibers were analyzed by the in-air particle induced X-ray emission (PIXE) method. Individual fibers were used as a target, representing minute material available in forensic or archeological applications. For quantification of the concentrations, the X-ray production was assumed to occur in a thin cylindrical target that intersects the central part of the beam. The irradiated volume and the distribution of escape lengths were calculated in the model. The impact beam intensity was axially symmetric Gaussian, as shown by calculation and cross-scan measurements. The normalization procedure relied on the argon signal from the air,whichwas checked by the choppermethod. For a set of fibers, elements characteristic of the fibers and their dressings were determined. Copyright © 2010 John Wiley & Sons, Ltd.

Abstract: Ion Beam Analysis (IBA) techniques are a powerful tool to study atmospheric aerosol composition, since they are quantitative, multi-elemental, fast, high-sensitivity and nondestructive analytical methods. At the 3 MV Tandetron accelerator of the LABEC laboratory of INFN in Florence an external beam facility is fully dedicated to measurements of elemental composition of atmospheric aerosols. All the elements with Z>10 are simultaneously detectable by Particle Induced X-ray Emission (PIXE) in few minutes of beam time, including several important tracers of peculiar aerosol sources and potentially harmful elements, with minimum detection limits ranging between 1 and 10 ng/m3. Light elements (H, C, N, O), which are the main aerosol constituents, can be detected by means of in-vacuum Particle Elastic Scattering Analysis (PESA). The application of both PIXE and PESA allows a complete mass reconstruction of aerosol samples. Since these methods are non-destructive, it is possible to apply complementary techniques, like Ion Chromatography, on the same samples, obtaining information, for example, on the chemical composition. Scanning possibility may also be very useful, allowing time trend reconstruction by the analysis of time-sequence aerosol deposits collected by continuous samplers. Using a two-stage “streaker” sampler the concentration time series of all the elements with Z>10 can be measured with hourly resolution. In this paper the peculiarity of these methods will be highlighted and the results of recent campaigns will be shown, including the application of IBA techniques to aerosol daily and hourly samples, collected in urban and industrial areas. © 2009 American Institute of Physics.

Abstract: Particle induced X-ray emission spectroscopy (PIXE) is now routinely used in the field of cultural heritage. Various setups have been developed to investigate the elemental composition of wood/canvas paintings or of cross-section samples. However, it is not possible to obtain information concerning the quantity of organic binder. Backscattering spectrometry (BS) can be a useful complementary method to overcome this limitation. In the case of paint layers, PIXE brings the elemental composition (major elements to traces) and the BS spectrum can give access to the proportion of pigment and binder. With the use of 3 MeV protons for PIXE and BS simultaneously, it was possible to perform quantitative analysis including C and O for which the non-Rutherford cross sections are intense. Furthermore, with the use of the same conditions for PIXE and BS, the experiment time and the potential damage by the ion beam were reduced. The results obtained with the external beam of the Accélérateur Grand Louvre pour l’Analyse Elémentaire (AGLAE) facility on various test painting samples and on cross sections from Italian Renaissance masterpieces are shown. Simultaneous combination of PIXE and BS leads to a complete characterization of the paint layers: elemental composition and proportion of the organic binder have been determined and thus provide useful information about ancient oil painting recipes.