SYNCHROTRON X-RAY MICROPROBE AND ITS APPLICATION TO HUMAN HAIR ANALYSIS

A synchrotron X-ray microprobe system based on Kirkpatrick-Baez optics has been developed. Double-crystal and synthetic multilayer monochromators are used for high energy resolution experiments and for highly sensitive X-ray fluorescence analysis, respectively. The characteristics of the X-ray microprobe were experimentally examined. A beam size of around 5 mum was obtained; the X-ray photon flux at the storage ring current of 300 mA is of the order of 10(7-8) photons/s and 10(9-10) photons/s for the double-crystal and multilayer monochromators, respectively. The concentration distributions of trace elements in cross sections of human hair were measured using an X-ray microbeam with the multilayer monochromator. Inhomogeneous distributions of trace elements in thin cross-section samples show that two-dimensional imaging is effective and indispensable both for the determination of the elemental concentration in hair and for investigating the incorporation mechanism of trace elements into hair from the body.