Electron-helium S-wave model benchmark calculations. I. Single ionization and single excitation

A full four-body implementation of the propagating exterior complex scaling (PECS) method [ J. Phys. B 37 L69 (2004)] is developed and applied to the electron-impact of helium in an S-wave model. Time-independent solutions to the Schrödinger equation are found numerically in coordinate space over a...

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Bibliographic Details
Main Authors: Bartlett, P., Stelbovics, Andris
Format: Journal Article
Published: American Physical Society 2010
Online Access:http://hdl.handle.net/20.500.11937/27967
Description
Summary:A full four-body implementation of the propagating exterior complex scaling (PECS) method [ J. Phys. B 37 L69 (2004)] is developed and applied to the electron-impact of helium in an S-wave model. Time-independent solutions to the Schrödinger equation are found numerically in coordinate space over a wide range of energies and used to evaluate total and differential cross sections for a complete set of three- and four-body processes with benchmark precision. With this model we demonstrate the suitability of the PECS method for the complete solution of the full electron-helium system. Here we detail the theoretical and computational development of the four-body PECS method and present results for three-body channels: single excitation and single ionization. Four-body cross sections are presented in the sequel to this article [ Phys. Rev. A 81 022716 (2010)]. The calculations reveal structure in the total and energy-differential single-ionization cross sections for excited-state targets that is due to interference from autoionization channels and is evident over a wide range of incident electron energies.