Conditions Influencing the Intensity of theΠ3−Σ1Cameron Bands of CO

Abstract

Conditions influencing the intensity of the ${}_{}{}^3{}_{}{}^{}\Pi -{}_{}{}^1{}_{}{}^{}\Sigma$ Cameron bands of CO in emission have been studied in detail in the electrodeless ring discharge. The bands are intense in a large discharge tube at a pressure of about 0.005 mm or less. Under these conditions the mean free time between collisions of CO molecules is 2.5×${10}^{-5\mathrm{}}$ sec. from which the lifetime of the ${}_{}{}^3{}_{}{}^{}\mathrm{II}$ state is estimated as about ten microseconds. Marked increases of intensity relative to that of other band systems in the same spectral region are produced by increasing the energy of the discharge and by lowering the pressure. This indicates that the excitation function of the Cameron system differs significantly from those of the systems with which it is compared.