We present experimental data on the dissociative recombination (DR) and the dissociative excitation (DE) of O2+ in its electronic and vibrational ground state using a heavy ion storage ring. The absolute DR cross section has been determined over an electron collision energy range from 1 meV to 3 eV. The thermal DR rate coefficient is derived; a(Te) = 2.4×10–7(300/Te)0.70±0.01cm3 s–1, for T>200 K. The threshold for DE was observed near its energetic threshold of 6.7 eV. The DE cross section curve has a maximum of 3×10–16 cm2 near 15 eV. We have determined the branching fractions to the different dissociation limits and present atomic quantum yields for the DR process between 0 to 300 meV collision energy. The quantum yield of O(1D) is found to be 1.17±0.05, largely independent of the electron energy. Arguments are presented that the branching fraction to O(3P) + O(1S) is negligible. The branching fraction to the O(1S) + O(1D) is smaller than 0.06 and varies strongly as a function of collision energy. The O(1S) quantum yield is a strong function of electron temperature. Hence, the relative strength of the green, O(1S), and the red, O(1D), airglows may be used as a measure of the electron temperature of the upper atmosphere. A qualitative explanation is given of the consequences of nonadiabatic interactions in the dissociation step of the DR process.

J. Chem. Phys.

Peverall, R, Rosén, S, Peterson, J. R, Larsson, M, Al Khalili, A, Vikor, L, … van der Zande, W. J. (2001). Dissociative recombination and excitation of O2+: Cross sections, product yields and implications for studies of the ionospheric airglows. J. Chem. Phys., 114, 6679–6689. doi:10.1063/1.1349079