Exchange Effects in Low Energy Electron Impact Ionization of the Inner and Outer Shells of Argon


First order distorted wave Born approximation (DWBA) triple differential cross sections are reported for low-energy electron-impact ionization of the inner 3s and outer 3p shells of argon. Previous DWBA works have demonstrated that experiment and theory are not in accord for low energy ionization of inert gases and here we investigate the importance of exchange scattering. Different approximations for treating exchange scattering are investigated. It is shown that exchange scattering is particularly important for 3s ionization. Even with a proper treatment of exchange, the first order calculations are still not in satisfactory agreement with experiment. Consequently higher order effects will have to be included to achieve a satisfactory description of the low-energy ionization process. We also investigated both the Hartree-Fock and optimized potential methods for calculating atomic wavefunctions and static potentials and found that both methods produced almost the same cross sections.



Keywords and Phrases

Approximation theory; Argon; Calculations; Electron energy levels; Electron scattering; Impact ionization; Optimization; Atomic wavefunctions; Distorted wave Born approximation; Hartree-Fock method; Low energy electron impact ionization; Optimized potential method; Static potentials; Triple differential cross section; Atomic physics

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Article - Journal

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© 2002 Institute of Physics - IOP Publishing, All rights reserved.

Publication Date

01 Jan 2002