On a selection of beam exit window materials for PIXE analysis

The effect of exit window materials on detection sensitivity in external PIXE analysis has been studied by measuring background excitation curves and by taking comparable spectra. Of the suitable low Z materials Be, Al and aluminized mylar were studied. Be is recommendable if the incident energy on Be is kept below the 2.06 MeV neutron threshold but above it the use of Be is highly questionable. Due to the high γ-background the use of Al-foil can be disregarded. If the main goal is high sensitivity aluminized mylar foil is the most advantageous. For the use of Al-mylar foil a simple beam exit arrangement provided with cooling was constructed. (orig.)