THE PHOTOELECTRIC ABSORPTION SPECTRUM OF OXYGEN AT ELEVATED TEMPERATURES (300 TO $1000^{\circ}K$) AT A BANDWIDTH OF 0.075{\AA} BETWEEN 1750 AND 2100{\AA} (SCHUMANN-RUNGE BANDS).

Abstract

The absorption of light by hot oxygen (300 to $1000^{\circ}K$) in the spectral region from 1750 to 2100 {\AA} has been investigated photoelectrically with a 2.2m McPherson scanning monochrometer at a bandwidth of 0.075{\AA}. The absorption chamber was a modification of that employed in this labortory in the study of alkali metal $vapors.^{1.2}$ At $600^{\circ}K$ the $v'' = 1$ bands are as strong as the corresponding $v'' = 0$ bands, and at $1000^{\circ}K$ the $v'' = 2, 3$ bands become apparent. Using selected Schumann-Runge lines measured previously by Curry and $Herzberg^{3}$ and Brix and $Herzberg.^{4}$ as standards, the wavelengths of these new lines have been measured to an estimated accuracy of $\pm 0.03${\AA}. Details of the experimental techniques, wavelength measurements, and the calculated spectroscopic constants of the $B ^{3}\Sigma^{-}_{u}$ state will be presented.