title: Optimization of the X-ray incidence angle in photoelectron spectrometers.
abstract: The interplay between the angle-dependent X-ray reflectivity, X-ray absorption and the photoelectron attenuation length in the photoelectron emission process determines the optimal X-ray incidence angle that maximizes the photoelectron signal. Calculations in the wide VUV to the hard X-ray energy range show that the optimal angle becomes more grazing with increasing energy, from a few tens of degrees at 50 eV to about one degree at 3.5 keV. This is accompanied by an intensity gain of a few tens of times, as long as the X-ray footprint on the sample stays within the analyzer field of view. This trend is fairly material-independent. The obtained results bear immediate implications for the design of (synchrotron-based) photoelectron spectrometers.
authors.affiliation: Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen-PSI, Switzerland. vladimir.strocov@psi.ch
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Strocov
keywords: X-ray absorption; photoelectron attenuation; photoelectron spectrometers; photoemission