Each new microscopy technique provides scientists with new perspectives on the function of living organisms and the nature of matter itself. This natural contrast makes it ideal for studying biological material. The condenser zone plate images the X-ray source demagnified through the pinhole onto the object. The highest resolution is obtained in XM by using zone plates as optics.
Zone plates are circular diffraction gratings with radial increasing line density.
The resolution of a zone plate is about equal to the width of the outermost zone. Today 30 nm structures are made routinely and 20 nm is state of the art. Aqueous samples are trapped between 2 silicon wafers with transmissive walls thinned to 150 nm in the central part and then mounted in a special target chamber. The liquid layer can be adjusted to a thickness of a few microns. Typical exposure times are several seconds.