Zernike phase-contrast x-ray microscope with pseudo-Kohler illumination generated by sectored (polygon) condenser plate

Zernike phase contrast x-ray microscope has been developed at the undulator beamline 20XU and 47XU of SPring-8. The system consists of a pseudo-Koehler-illuminating system, a Fresnel zone plate objective with outermost zone width of 100 nm, a Zernike phase plate (0.96-μm-thick tantalum, λ/4 or 3λ/4 phase-shifter at 8 keV) installed at the back-focal plane of the objective, and a visible-light conversion type cooled CCD camera as an image detector. A sectored (polygon) condenser plate is employed as the condenser in order to secure a large and flat field of view. Details and experimental results of the system will be shown.