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Title: Contributions of excitation autoionization to electron-impact ionization of Mg-like Al/sup +/, S/sup 4 +/, Cl/sup 5 +/, and Ar/sup 6 +/ ions

Abstract

The R-matrix method is used to calculate the contributions of excitation autoionization to electron-impact ionization in Mg-like Al/sup +/, S/sup 4 +/, Cl/sup 5 +/, and Ar/sup 6 +/ ions. The ground 3s/sup 2/ /sup 1/S state together with the autoionizing states arising from the 2p/sup 5/3s/sup 2/3p, 2p/sup 5/3s/sup 2/3d, 2p/sup 5/3s/sup 2/4s, 2s2p/sup 6/3s/sup 2/3p, 2s2p/sup 6/3s/sup 2/3d, and 2s2p/sup 6/3s/sup 2/4s configurations are included in the R-matrix expansion. Large numbers of bound terms of appropriate symmetry are included in the expansion to account for the resonant-excitation--double-autoionization process. The total ionization cross sections are obtained by combining the cross sections for inner-shell excitation with direct-ionization cross sections. Our calculation shows an abrupt and significant rise in the cross sections, in agreement with recent crossed-beam measurements of Howald et al. The importance of indirect processes over the direct process increases with increasing ionic charge along the sequence.

Authors:
;
Publication Date:
Research Org.:
Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803-4001
OSTI Identifier:
5732234
Resource Type:
Journal Article
Journal Name:
Phys. Rev. A; (United States)
Additional Journal Information:
Journal Volume: 33:6
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ALUMINIUM IONS; ELECTRON-ION COLLISIONS; ARGON IONS; CHLORINE IONS; IONIZATION; SULFUR IONS; AUTOIONIZATION; EXCITATION; ISOELECTRONIC ATOMS; MULTICHARGED IONS; R MATRIX; TOTAL CROSS SECTIONS; ATOMS; CHARGED PARTICLES; COLLISIONS; CROSS SECTIONS; ELECTRON COLLISIONS; ENERGY-LEVEL TRANSITIONS; ION COLLISIONS; IONS; MATRICES; 640304* - Atomic, Molecular & Chemical Physics- Collision Phenomena

Citation Formats

Tayal, S S, and Henry, R J.W. Contributions of excitation autoionization to electron-impact ionization of Mg-like Al/sup +/, S/sup 4 +/, Cl/sup 5 +/, and Ar/sup 6 +/ ions. United States: N. p., 1986. Web. doi:10.1103/PhysRevA.33.3825.
Tayal, S S, & Henry, R J.W. Contributions of excitation autoionization to electron-impact ionization of Mg-like Al/sup +/, S/sup 4 +/, Cl/sup 5 +/, and Ar/sup 6 +/ ions. United States. doi:10.1103/PhysRevA.33.3825.
Tayal, S S, and Henry, R J.W. Sun . "Contributions of excitation autoionization to electron-impact ionization of Mg-like Al/sup +/, S/sup 4 +/, Cl/sup 5 +/, and Ar/sup 6 +/ ions". United States. doi:10.1103/PhysRevA.33.3825.
@article{osti_5732234,
title = {Contributions of excitation autoionization to electron-impact ionization of Mg-like Al/sup +/, S/sup 4 +/, Cl/sup 5 +/, and Ar/sup 6 +/ ions},
author = {Tayal, S S and Henry, R J.W.},
abstractNote = {The R-matrix method is used to calculate the contributions of excitation autoionization to electron-impact ionization in Mg-like Al/sup +/, S/sup 4 +/, Cl/sup 5 +/, and Ar/sup 6 +/ ions. The ground 3s/sup 2/ /sup 1/S state together with the autoionizing states arising from the 2p/sup 5/3s/sup 2/3p, 2p/sup 5/3s/sup 2/3d, 2p/sup 5/3s/sup 2/4s, 2s2p/sup 6/3s/sup 2/3p, 2s2p/sup 6/3s/sup 2/3d, and 2s2p/sup 6/3s/sup 2/4s configurations are included in the R-matrix expansion. Large numbers of bound terms of appropriate symmetry are included in the expansion to account for the resonant-excitation--double-autoionization process. The total ionization cross sections are obtained by combining the cross sections for inner-shell excitation with direct-ionization cross sections. Our calculation shows an abrupt and significant rise in the cross sections, in agreement with recent crossed-beam measurements of Howald et al. The importance of indirect processes over the direct process increases with increasing ionic charge along the sequence.},
doi = {10.1103/PhysRevA.33.3825},
journal = {Phys. Rev. A; (United States)},
number = ,
volume = 33:6,
place = {United States},
year = {1986},
month = {6}
}