A zone plate soft x‐ray microscope using monochromatized undulator radiation at the beamline NE1B of the TRISTAN Accumulation Ring

A soft x‐ray microscope has been developed at the beamline NE1B of the 6.5‐GeV TRISTAN Accumulation Ring (AR). It makes use of undulator radiation as its source and a zone plate with the outermost zone width of 50 nm as its imaging element. It has two main features. First, the undulator radiation is monochromatized by a grazing incidence grating monochromator to match to the monochromaticity requirement of the zone plate. Second, a visible light prefocus unit consisting of two objectives has been designed and installed in the x‐ray microscope. The x‐ray optical system of the microscope can be adjusted easily, quickly, and precisely by using this unit. The microscope can resolve 55‐nm lines and spaces in a zone plate test pattern.