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Measurements of the reaction rates of O ++ ions with N 2 and O 2 at thermal energy and their ionospheric implications
Author(s) -
Johnsen Rainer,
Biondi Manfred A.
Publication year - 1978
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl005i010p00847
Subject(s) - ion , atomic physics , physics , ionosphere , f region , analytical chemistry (journal) , thermal , chemistry , thermodynamics , geophysics , chromatography , quantum mechanics
A drift‐tube mass‐spectrometer apparatus has been used to determine the rate coefficients for the loss of O ++ ions by charge transfer on collisions with N 2 and O 2 molecules. At 300 K the respective coefficients are (1.3 ± 0.3) × 10 −9 and (1.5 ± 0.3) × 10 −9 cm³/sec. Even at F‐region temperatures these reactions should be fast, since the rate coefficients for reactions of this type vary only slightly with increase in temperature. However, in the recent model calculations of Breig et al, the AE measurements of the O ++ altitude profiles are only reproduced if the O ++ + N 2 rate coefficient is assumed to be much smaller than 10 −10 cm³/sec. Thus we conclude that important sources of O ++ ions have been omitted from the model.