The CoESCA station at BESSY: Auger electron–photoelectron coincidences from surfaces demonstrated for Ag MNN
Journal article, 2021
In this work, we present the CoESCA station for electron–electron coincidence spectroscopy from surfaces, built in a close collaboration between Uppsala University and Helmholtz-Zentrum Berlin at the BESSY II synchrotron facility in Berlin, Germany. We start with a detailed overview of previous work in the field of electron–electron coincidences, before we describe the CoESCA setup and its design parameters. The system is capable of recording shot-to-shot resolved 6D coincidence datasets, i.e. the kinetic energy and the two take off angles for both coincident electrons. The mathematics behind extracting and analysing these multi-dimensional coincidence datasets is introduced, with a focus on coincidence statistics, resulting in fundamental limits of the signal-to-noise ratio and its implications for acquisition times and the size of the raw data stream. The functionality of the CoESCA station is demonstrated for the example of Auger electron–photoelectron coincidences from silver surfaces for photoelectrons from the Ag 3d core levels and their corresponding MNN Auger electrons. The Auger spectra originating from the different core levels, 3d and 3d could be separated and further, the two-hole state energy distributions were determined for these Auger decay channels.
Spectroscopy
Coincidence
APECS
PES
Auger
Surface science
AES
Photoelectron
Author
T. Leitner
Uppsala-Berlin joint Laboratory
Helmholtz
A. Born
Helmholtz
University of Potsdam
I. Bidermane
Uppsala-Berlin joint Laboratory
Helmholtz
Ruslan Ovsyannikov
Uppsala-Berlin joint Laboratory
Helmholtz
Fredrik O.L. Johansson
Uppsala University
Yasmine Sassa
Chalmers, Physics, Materials Physics
A. Föhlisch
Uppsala-Berlin joint Laboratory
Helmholtz
Andreas Lindblad
Uppsala University
Uppsala-Berlin joint Laboratory
F. O. Schumann
Max Planck Society
S. Svensson
Uppsala University
Uppsala-Berlin joint Laboratory
N. Martensson
Uppsala-Berlin joint Laboratory
Uppsala University
Journal of Electron Spectroscopy and Related Phenomena
0368-2048 (ISSN)
Vol. 250 147075Subject Categories
Atom and Molecular Physics and Optics
Other Physics Topics
Condensed Matter Physics
DOI
10.1016/j.elspec.2021.147075