Diagnostics of collisions between electrons and water molecules in near-ultraviolet and visible wavelengths
| Main Authors: | Bodewits, Dennis, Országh, Juraj, Noonan, John, Ďurian, Michal, Matejčík, Štefan |
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| Format: | info publication-preprint Journal |
| Terbitan: |
, 2019
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/3700511 |
Daftar Isi:
- We studied dissociation reactions of electron impact on water vapor for several fragment species at optical and near ultraviolet wavelengths (200 - 850 nm). The resulting spectrum is dominated by the Hydrogen Balmer series, by the OH (A 2Σ+ - X 2Π) band, and by the emission of ionic H2O+ (A 2A1 - X 2B1) and OH+ (A 3Π - X 3Σ−) band systems. Emission cross sections and reaction channel thresholds were determined for energies between 5 - 100 eV. We find that electron impact dissociation of H2O results in an emission spectrum of the OH (A 2Σ+ - X 2Π) band that is distinctly different than the emission spectra from other excitation mechanisms seen in planetary astronomy. We attribute the change to a strongly non-thermal population of rotational states seen in planetary astronomy. This difference can be utilized for remote probing of the contribution of different physical reactions in astrophysical environments