Electronic excitation and dissociation of the methane molecule upon electron impact at low energies
- Lawrence Livermore National Laboratory, CA (United States)
Complex-Kohn calculations of electron impact excitation of the methane molecule are presented. This system has Rydberg states that are all presumed to be dissociative so comparisons with measurements of electron-impact dissociation cross sections are made. The 3s, 3p and 3d-type Rydberg orbitals were used to construct 54 excited target states. Atomic-like selections rules were applied to organize those states in groups for which channel coupling is expected to be significant. In those groups close-coupling formulation of the complex-Kohn method was used to calculate electronic excitation cross sections. The largest such group includes 16 coupled states. The present results are found to be in adequate agreement with measurements of total electron scattering cross sections. Although the present calculations are quite extensive questions remain about the adequacy of the target state expansions used. Our electronic excitation cross sections are larger than some measurements of the total dissociation indicating coupling to ionization channels or redistribution of magnitudes due to interchannel coupling that was not taken into account.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 281326
- Report Number(s):
- CONF-9305421--
- Journal Information:
- Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 3 Vol. 38; ISSN 0003-0503; ISSN BAPSA6
- Country of Publication:
- United States
- Language:
- English
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