The associative ionization of N(2P) + O(3P) revisited

The room temperature rate constant for the reaction of N(2P) + O(3P) has been measured using a flow tube apparatus by monitoring the concentrations of both reactants via absorption spectroscopy and simultaneously monitoring the associative ionization product, NO+, using time-of-flight mass spectrometry. A value of 2.5 ± 1.3 × 10−11 cm3 s−1 is reported along with a lower limit on the product branching fraction for associative ionization (as opposed to quenching) of 0.5 and likely much larger, >0.9.