title: Near field and exit wave computations for electron microscopy.
abstract: The partial wave phase shift formalism of atomic scattering is applied to compute exit wave functions for isolated Au and Si atoms under both plane wave and focused probe illumination. Connections between the far field and near field (exit) waves are clarified. This approach treats the Coulomb singularity properly though at 100 keV large numbers of phase shifts are required. In principle any form of incident wave can be handled so it may provide a means for testing traditional scattering theories used in electron microscopy. By applying the analysis to an atom embedded in a constant potential rather than free space, exit spheres of radius half the interatomic spacing can be used.
authors.affiliation: Department of Physics, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UK. Electronic address: ah30@cam.ac.uk.
authors.forename: A
authors.initials: A
authors.lastname: Howie
mesh_terms: D055032:Electron Microscope Tomography / Q000379:methods*; D017348:Microscopy, Electron, Scanning Transmission / Q000379:methods*
keywords: Atomic exit waves; Far field and near field; Scattering and phase shifts