Absolute Chemiluminescent Reaction Rates for Emission of the O2Herzberg Bands in Oxygen and Oxygenndash;Inerthyphen;Gas Afterglows

摘要

Chemiluminescent reaction rates for emission of the O2Herzberg bands in the O2and O2thinsp;plus;thinsp;He or Ar afterglows have been measured in a dischargehyphen;flow system. Absolute intensities were measured between 260.0 and 420.0 nm at 0.5hyphen;nm resolution with a scanning spectrometer, and oxygenhyphen;atom densities were determined by NO2titration. Intensities were obtained as a function of atom density, O2pressure, and partial pressures of added nonreactive gases. The integrated intensity of the Herzberg band system is proportional to O2and independent of O2pressure between 1 and 10 torr. TheA3Sgr;uplus;state of O2is quenched by groundhyphen;state O2, and the Herzberg bands are stronger in mixtures of O2with He or Ar than in pure O2. The chemiluminescent reaction rate coefficient is 2.5thinsp;times;thinsp;10minus;21cm3/sec in O2and is larger by about a factor of 10 in He or Ar. The vibrational population distribution is shifted to lower vibrational levels ofO2lpar;A3Sgr;uplus;rpar;in the O2ndash;inerthyphen;gas mixtures than in pure O2.