X-ray Microscope

1,172,327. X-ray microscope. D. RUDOLPH and G. SCHMAHL. 5 March, 1968 [20 March, 1967], No. 10505/68. Heading H5B. An X-ray microscope in which the beam is focused by means of zone plates. These plates which consist of a series of concentric annuli around a central core such that each alternate annulus is constituted by either an X-ray transparent or X-ray opaque material may be constructed having dimensions such that they will bring a beam of X-rays to a focus by exposing a light-sensitive layer to the interference figure produced when a planar wave is superimposed on a spherical wave or one spherical wave is superimposed on another. The zone plane may be supported on a plate of quartz glass, metal or plastics material on to which one or several image layers are applied or the zone plane may be self supporting. The support preferably comprises spaced concentric annular zone rings with radial connecting webs. Zone plates of desirably smaller dimensions may be produced by reducing the size of a master zone plate by electron optical means. The zone plate optical system 2, 3 (Fig. 1) may be provided as a condenser between X-ray source 1 and object 4 so as to illuminate the object. Further zone plate systems 5, 3 and 7, 3 may be positioned as objectives to produce a magnified image of the object, the final image being rerecorded on image recording device 9. If Fig. 2 (not shown), the zone plates utilized as objectives are dispensed with, a shadowgraph of the strongly illuminated image is produced. The focusing effect of the zone plates is achieved by diffraction.