High energy resolution PIXE analysis using focused MeV heavy ion beams

The possibility of chemical state microanalysis using high energy resolution PIXE was investigated using a plane crystal spectrometer installed at a heavy ion microbeam line, The spectrometer has the advantage for the analysis of an X-ray spectrum of simultaneously detecting X-rays over an energy range using position sensitive proportional counter without scanning the crystal. Though the detection efficiency is estimated to be at least four orders of magnitude lower than energy dispersive X-ray spectroscopy (EDS) using a Si(Li) detector, the resolution of the system (dE/E) is better than 10(-3). because the effect of beam size on system resolution is negligible. Focused 2 MeV proton and 5 MeV Si3+ ion beams were employed for the analysis of Si Kr X-rays of Si and SiO2. In both cases, it is possible to detect chemical effects by observing relative intensities of X-ray satellite peaks. However, the use of heavy ions is considered to be more promising because the yields of satellite lines using silicon ion bombardment was much higher than that of protons. (C) 1998 Elsevier Science B.V.