Absolute Chemiluminescent Reaction Rates for Emission of the O2 Herzberg Bands in Oxygen and Oxygen–Inert-Gas Afterglows
1969; American Institute of Physics; Volume: 51; Issue: 7 Linguagem: Inglês
10.1063/1.1672441
ISSN1520-9032
AutoresR. J. McNeal, Stephen C. Durana,
Tópico(s)Air Quality Monitoring and Forecasting
ResumoChemiluminescent reaction rates for emission of the O2 Herzberg bands in the O2 and O2 + He or Ar afterglows have been measured in a discharge-flow system. Absolute intensities were measured between 260.0 and 420.0 nm at 0.5-nm resolution with a scanning spectrometer, and oxygen-atom densities were determined by NO2 titration. Intensities were obtained as a function of atom density, O2 pressure, and partial pressures of added nonreactive gases. The integrated intensity of the Herzberg band system is proportional to [O]2 and independent of O2 pressure between 1 and 10 torr. The A 3Σu+ state of O2 is quenched by ground-state O2, and the Herzberg bands are stronger in mixtures of O2 with He or Ar than in pure O2. The chemiluminescent reaction rate coefficient is 2.5 × 10−21 cm3/sec in O2 and is larger by about a factor of 10 in He or Ar. The vibrational population distribution is shifted to lower vibrational levels of O2(A 3Σu+) in the O2–inert-gas mixtures than in pure O2.
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