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- Title
Cross Sections and Rate Coefficients for O<sup>+</sup> Reacting With N<sub>2</sub>, O<sub>2</sub>, and NO.
- Authors
Viehland, Larry A.; Johnsen, Rainer
- Abstract
Ion‐molecule reaction cross sections between 0.03 and 3 eV can best be inferred from data taken in drift tube mass spectrometers. For the title reactions, the cross sections inferred from drift‐tube measurements in the late 1970s have been accepted as accurate, even though the methods used to infer them made substantial assumptions about the ion velocity distribution functions. Here the Gram‐Charlier method for solving the Boltzmann equation is used to obtain ion distribution functions that are anisotropic, having different average energies parallel and perpendicular to the uniform electrostatic field. The Gram‐Charlier method incorporates skewness, kurtosis, and correlation between the motions parallel and perpendicular to the field. This leads to more accurate ion distribution functions from which more accurate reaction cross sections have been inferred. The results differ by as much as 50% from the generally accepted cross sections that are currently used to model ion‐neutral reactions in the upper atmosphere. Key Points: Drift‐tube measurements of the rate coefficients for the title reactions are reanalyzedThe results indicate that the reaction cross sections previously extracted from the data are in significant errorNew, improved cross sections are inferred from the data for energies between 0.03 and 3 eV
- Subjects
RATE coefficients (Chemistry); ION-molecule collisions; ION migration &; velocity; BOLTZMANN'S equation; KURTOSIS
- Publication
Journal of Geophysical Research. Atmospheres, 2019, Vol 124, Issue 23, p13593
- ISSN
2169-897X
- Publication type
Article
- DOI
10.1029/2019JD031186