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Journal of Spectroscopy
Volume 2014, Article ID 152647, 8 pages
Research Article

Simulation of Electron Energy Spectra of a Biased Paracentric Hemispherical Deflection Analyzer as a Function of Entry Bias: Effects of Misalignments

Department of Science Education, Faculty of Education, Suleyman Demirel University, 32260 Isparta, Turkey

Received 27 January 2014; Accepted 26 March 2014; Published 16 April 2014

Academic Editor: Eugen Culea

Copyright © 2014 O. Sise. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The performance of a biased paracentric hemispherical deflection analyzer (HDA), including fringing fields and their effect on focusing and energy resolution, is investigated using numerical methods. Electron energy spectra are calculated for three entry positions  mm, 100 mm, and 112 mm and compared with the recent experimental measurements. In both experiment and calculation, the two different paracentric entry positions  mm and  mm, on either side of the mean radius of 100 mm, are found to have a base energy resolution of about two times better than the conventional centric entry position  mm. In order to explain the discrepancies (6–30%) between the simulated and the experimental resolutions the focusing characteristics are further investigated for different displacements of the input lens ( ) with respect to the entry position and the tilted input beam axis by in the dispersive direction. We have found that the blame does not in fact lie with the theory and we have shown that the input lens may have been misaligned in the experiment. Slight misalignments affect both the true energy resolution measurement and the transmission of the beam.