High-resolution energy analyzer for photoelectron diffraction studies

This paper presents a design of a novel instrument for X-ray photoelectron diffraction and X-ray photoelectron holography measurements—compact electron spectrometer characterized by a high sensitivity as well as a high energy and spatial resolution. The design is based on a combination of axially symmetric 90° sector spherical deflector with second-order spatial focusing preceded by hollow conical deceleration immersion lens. The range of photoelectron energies, accepted by the spectrometer, varies from 0 up to several thousand electron volts, so that the analyzer can be used for studies of both valence and core electron levels. The analyzer can provide (with the radius of the beam path inside the spherical deflector of 50 mm) for the energy resolution of ΔE/E=10−4. This resolution can be achieved in angle-resolved experiments with the angular resolution of 0.25° for electrons collected from the extended area on the sample plane up to 4 mm2 or more and the range of initial polar or azimuthal angles up to 60°. Alternatively, the same resolution can be achieved in the spectromicroscopy mode, with the accepted solid angle of 0.5 sr. In both cases, the acceptance of the analyzer is about an order of magnitude larger than the acceptance of high-resolution energy analyzers conventionally used in such studies.