Electron-Impact Ionization Cross Sections for Polyatomic Molecules, Radicals, and Ions

Published

March 1, 2000

Author(s)

Yong Sik Kim, Karl Irikura

Abstract

The binary-encounter-Bethe (BEB) model for calculating electron-impact ionization cross sections for molecules is described with emphasis on polyatomic molecules and their radicals and ions. The BEB model provides an analytic formula for the cross section. The formula is for each molecular orbital, and requires only three numbers from the initial state of the target molecule: the electron occupation number, the orbital binding energy, and the orbital kinetic energy. The sum of the orbital cross sections provides the molecular cross section. The BEB model produces reliable ionization cross sections from the threshold to several keV in incident electron energy for neutral molecules and ions. The BEB cross sections for some fluorine-containing radicals are almost a factor of two larger than available experiments. Molecular constants are included to generate BEB cross sections for H₂, C₂F₆, WF₆, H₂+, CH₃, CF_x, BF_x, BCl_x, and NF_x for x=1-3, C_nH_m for n=2-5 and m=2-10.

Proceedings Title

AIP Conference Proceedings Volume 543 ATOMIC AND MOLECULAR DATA AND THEIR APPLICATIONS: ICAMDATA Second International Conference

Volume

543

Conference Dates

March 26-30, 2000

Conference Location

Oxford, UK

Conference Title

ATOMIC AND MOLECULAR DATA AND THEIR APPLICATIONS: ICAMDATA Second International Conference

Pub Type

Conferences

Keywords

electron-impact ionization, ions, polyatomic molecules, radicals

Citation

Kim, Y. and Irikura, K. (2000), Electron-Impact Ionization Cross Sections for Polyatomic Molecules, Radicals, and Ions, AIP Conference Proceedings Volume 543 ATOMIC AND MOLECULAR DATA AND THEIR APPLICATIONS: ICAMDATA Second International Conference, Oxford, UK (Accessed May 9, 2026)

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