Soft x‐ray microscope at the undulator beamline of the Photon Factory

A soft x‐ray microscope using Fresnel zone plates as optical imaging elements was installed at the Photon Factory. It makes use of undulator radiation as a source of soft x rays ranging from 2.0 to 3.0 nm in wavelength. The optical system was designed to match to the undulator radiation. A performance test was made at 2.66 nm by various pitches of transmission gratings. Those magnified images were taken with a magnification of 230 and exposure times of about 10 s. The modulation transfer function was measured over the spatial frequency up to 3300 lp/mm. Further, magnified images of some biological specimens were obtained.