Fig. 1.1 shows a schematics of the scanning transmission x-ray microscope. All elements up to the Fresnel zone plate are covered in the beamline manual, which you can find on http://xray1.physics.sunysb.edu/user/manuals.php. The Fresnel zone plate (ZP) focuses a coherent x-ray beam to a spot. Unwanted diffraction orders are filtered out with a pinhole called order-sorting aperture (OSA). The image is formed by scanning the sample through the focal spot in X and Y, and recording the total transmitted intensity for each scan pixel with a detector.