External Ion Beam End-Station

The external ion beam analysis end-station integrates the analytical capabilities of the PIXE, RBS and PIGE ion beam analysis techniques in one experimental set-up, so that to attain a complete elemental and near surface structural characterization of samples in an almost non-destructive way and without any limitation concerning their size or conductive state. The set-up experimental was developed to be used with protons as well as with heavier ions. Probe dimensions down to ≈1 mm2 can be analyzed.

It uses simultaneously five spectrometers; two for the implementation of PIXE by utilizing newly acquired Silicon Drift detectors (SDDs) with 30mm2 and 150 mm2 active areas supported by digital pulse processors, one for RBS/NRA, one for PIGE, whereas an additional miniature SDD X-ray detector is also employed for dose monitoring purposes. The exit ion-beam nozzle through appropriate collimation confines the ion beam size (≈1mm at the analysis point), whereas the selected exit window (100 nm Si3N4 thin film) and the short distance (≈5mm), in which the charged particles travel across the air path, minimize the ion beam energy loss and the straggling effect.

Up to date, the setup has been employed in analytical diagnostic studies of a few representative paintings of contemporary Greek painters in order to identify and document pigments, materials and techniques and prevent trade of fakes. In addition, ancient glass beads were also examined with respect to their sodium concentration and their in-depth homogeneity.