Scanning hard X-ray microscope with tantalum phase zone plate at the Hyogo-BL (BL24XU) of SPring-8

A scanning hard X-ray microscope using a phase zone plate made of tantalum as its X-ray focusing device is in operation at the Hyogo-BL (BL24XU) of SPring-8. The X-ray microbeam has a size of 0.8 μm×0.7 μm at the photon energy of 10 keV, which can make visible structures as fine as 250-nm line-and-space pattern. The photon flux density at the sample position is ∼2×109 phs/s/μm2 and the gain of the phase zone plate is ∼3000. The minimum detection limits irradiated by the microbeam are evaluated to be around 10 ppm for some trace elements contained in standard reference materials of glass matrices. X-ray images obtained so far demonstrate a high feasibility of the microscope.