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Sources of Internal Scattering of Electrons in a Cylindrical Mirror Analyser (CMA)
Author(s) -
El Gomati M. M.,
El Bakush T. A.
Publication year - 1996
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/(sici)1096-9918(199603)24:3<152::aid-sia96>3.0.co;2-j
Subject(s) - analyser , scattering , optics , electron , cylinder , physics , aperture (computer memory) , detector , forward scatter , signal (programming language) , spectrometer , computational physics , nuclear physics , geometry , acoustics , mathematics , computer science , programming language
A number of possible sources of internal scattering of electrons in a single‐pass Varian cylindrical mirror analyser (CMA) have been identified and their relative contributions to the electron spectral background evaluated. These sources include: the inner surfaces of the outer cylinder; the input and output apertures of the inner cylinder; thefield trimmers between the two cylinders; the walls of the exit aperture in front of the electron detector; the outersurfaces of the inner cylinder. A theory/experiment comparison of the above sources has verified that the two most significant of these are the walls of the exit aperture and the field trimmers. The other sources contribute only negligibly to the total signal of internally scattered electrons. Simple modifications of the spectrometer and its detector show a large reduction in the internal scattering signal. A simple experimental measurement for determining the relative contribution of the various internal scattering sources is suggested. This measurement is recommended instead of the commonly used peak‐to‐background ratios as a diagnostic tool for detecting and evaluating all the above‐mentioned sources of internal scattering of electrons in a CMA.