A portable semi-micro-X-ray fluorescence spectrometer for archaeometrical studies

A portable semi-micro-X-ray fluorescence (μ-XRF) spectrometer was developed in the Laboratory for Material Analysis of the N.C.S.R “Demokritos”. It utilizes a novel end-window, battery-operated, low-power X-ray tube (40 kV, 40 μA) with Au as anode material, a peltier cooled Si-PIN X-ray detector and associated electronics. The unique design of the probe-like X-ray tube anode allows very close coupling of any optical component to the tube anode, as well as to the sample position. A 240 μm pin-hole collimator was used to form the semi-microbeam. Monte Carlo calculations, as well as several sets of measurements, were performed, in order to determine the optimum geometrical and operational parameters. Preliminary results about the performance of our spectrometer are presented and compared to those reported in the literature for other micro-XRF instruments utilizing various optical elements (pin-holes, poly-capillary lenses) for focusing X-rays. The potential of this semi-micro-XRF spectrometer in the archaeometrical research is also discussed.