UBC Theses and Dissertations
Studies on the afterglow of nitrogen and oxygen discharges Ashford, Robert D.
The reactions: [formulae omitted] have been studied here in a discharge flow system. Using two temperatures, the rate constant for wall deactivation was found to be 3.8 x 10² exp [fomula omitted] sec⁻¹. It was concluded that the deactivation was not diffusion controlled as previously suggested but controlled by the surface deactivation process on the walls. The rate constant for production of O₂(¹Σg＊) was found to be 6.7 x 10⁴ exp [formula omitted] litres mole⁻¹sec⁻¹, in reasonable agreement with the room temperature value determined by Arnold. An upper limit of 1.6 x 10⁴ litres mole⁻¹sec⁻¹ was obtained for the rate constant of the reaction: N + O₂ (¹Δg ) → NO + 0 showing that the reaction is considerably slower than expected from comparison with the analogous reaction of ground state oxygen. This is rationalized by showing that the two reactions require different transition states. Whilst studying the above reaction several surface catalysed glows from molecular nitrogen and nitric oxide were seen. These glows were found to require O₂ (¹Δg) for their production and not atomic oxygen as previously thought. Several qualitative and spectroscopic experiments were performed and in the light of the information gained various possible mechanisms are discussed.
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