10 keV X-ray phase-contrast microscopy for observing transparent specimens

Hard X-ray phase-contrast microscopy has been performed with phase plates o f tantalum using an X-ray beam from an undulator in SPring-8. The photon en ergy was set at 10 keV near the L-3 absorption edge of tantalum (9.9 keV) i n order to increase the phase contrast. To demonstrate its capability, a tr ansparent specimen was imaged clearly in the reverse contrast with phase pl ates to shift the phase by one-quarter and three-quarters of a period, whil e conventional absorption imaging showed little contrast. Further, an image contrast as high as approximately 40% can be obtained for the cell walls o f another specimen.