Konferans bildirisi Açık Erişim

Comparison of fringing field correction schemes for the 180 degrees hemispherical deflector analyzer

2008    Sise, Omer; Zouros, Theo J. M.; Ulu, Melike; Dogan, Mevlut

It is well known that apertures placed at the entrance and exit planes of a hemispherical deflector-type analyzer distort the ideal 1/r(2) field behaviour, which modifies the central electron trajectories and degrades the energy resolution of the analyzer. In this work, we have carried out trajectory simulations for the 180 degrees hemispherical deflector analyzer (HDA) to obtain the energy resolution numerically for the following fringing field correction schemes: Herzog plates, Jost correctors, tilted input lens, end-field terminators, and the newly reported biased paracentric entry. The biased paracentric entry HDA is shown to be advantageous over conventional designs, enjoying greater dispersion and therefore better energy resolution for a given entrance and exit size apertures, improved focusing characteristics and sharper transmission. Tedious fringing field correction schemes can therefore be avoided of particular interest to investigators using modern HDAs. (C) 2008 Elsevier B. V. All rights reserved.