Electron Production by Associative Detachment of O– Ions with NO, CO, and H2

Abstract

Electron currents resulting from associative‐detachment processes involving O^– ions have been observed in a drift tube containing mixtures of oxygen and either hydrogen, carbon monoxide, or nitric oxide. The associative‐detachment rate coefficients are obtained from analyses of the electron current waveforms. The results indicate that the associative detachment proceeds by a two‐body process. The observed rate coefficients are consistent with results obtained from studies of O^– destruction using mass spectrometric techniques. Associative detachment rate coefficients of 2.2, 6.5, and 7.5 × 10^− 10 cm³ sec^− 1 have been measured at near‐thermal ion energies for the O^– + NO, O^– + CO, and the O^– + H₂ reactions, respectively. The average energy of the O^– ions ranged from thermal up to 0.16 eV. A search for a reaction between O₂^– and CO was unsuccessful indicating that the rate coefficient of this reaction is less than 10^− 14 cm³ sec^− 1.