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The article describes the ESCA microscopy beamline dedicated to high spatial resolution quantitative and qualitative analysis on surfaces and interfaces. The scanning microscope is constructed to work both in transmission and photoemission within the photon energy range from 200 to 1200 eV with a spatial resolution of ∼0.1 μm. A Fresnel zone plate demagnifies the photon beam to submicrometer dimensions with 109–1010 photons/s in the focus spot. A photodiode and a hemispherical electron energy analyzer are used as detectors for recording the transmitted x‐rays and emitted photoelectrons, respectively. The operation modes in photoemission give the opportunity to obtain conventional energy distribution curve spectra from a microspot or a two‐dimensional micrograph of the spatial distribution and local concentration of a selected element as the sample is mechanically scanned. For conductive specimen topography measurements of a selected surface area probed by SPEM are possible using a scanning tunnelling microscope. The first test images of a zone plate and an e‐beam written specimen with 1 μm2 Au squares on Si have shown a spatial resolution better than 0.2 μm.

The concept of variation of the angle of deflection in a spherical grating monochromator allows to keep the defocus aberration at zero while keeping the entrance and the exit slit distances fixed. This report presents the optimization of this concept for different applications in which one would always like to work with maximum resolving power and photon flux while keeping the exit slit at a fixed position. Three designs are presented for medium resolution (E/ΔE = 3000) soft x‐ray microscopy studies in the photon energy range 200–1200 eV and 20–300 eV and for high‐resolution spectroscopy (E/ΔE≳10 000) in the larger range 20–800 eV.

A possible design for a spherical grating monochromator is based on the translation of the entrance slit in order to minimize the system aberrations during the wavelength scan. This configuration has been studied both analytically and by means of extended ray‐tracing calculations and the design and performance of such a monochromator are discussed. In order to verify advantages and limitations of this solution a systematic comparison with a spherical grating monochromator with a moveable exit slit has been performed.