Kinetic study of electronically excited nitrogen atoms, N(22DJ, 22PJ), by attenuation of atomic resonance radiation in the vacuum ultra-violet

Abstract

The collisional behaviour of electronically excited nitrogen atoms, N(2²D_J,2²P_J), has been investigated by atomic absorption spectroscopy using time-resolved attenuation of resonance radiation in the vacuum ultra-violet. The optically metastable atoms have been generated by the repetitive, pulsed irradiation of nitrous oxide in the Schumann region and the resulting photoelectric pulses representing the concentration profiles of the atomic states have been signal averaged. This system has involved the use of a rapid response logarithmic signal converter, capable of measuring directly in (I₀/I_tr) for a weak, fast decaying signal. This has permitted quenching rate constants to be determined with an accuracy considerably improved upon those obtained previously from “single-shot” measurements. Deactivation rate constants are reported for N(2²D_J) and N(2²P_J) with the gases H₂, N₂, O₂, CO, NO, CO₂ and N₂O and compared with those from earlier determinations.