An Investigation of the Effect of High Temperature on the Schumann-Runge Ultraviolet Absorption Continuum of Oxygen

A theoretical and experimental investigation of the absorption coefficient of molecular oxygen at high temperature is reported here. The wavelength range covered is in the vacuum ultraviolet region from 1300 A to 1740 A. The theoretical treatment covers all temperatures from 300° to 10,000° K. The experimental investigation was carried out in the temperature range of 4,000° to 10,000° K. All values of the absorption coefficient found apply only to oxygen for which the vibrational degree of freedom is fully excited.

The final results for the high temperature absorption coefficient as a function of temperature and wavelength are listed in table I. The experimental values found are plotted on figure 36. The estimated uncertainty of the experimental values is of the order of 10 percent except for the oxygen-argon results, which give absorption coefficients up to 200 percent larger than oxygen. The experimental scatter of the oxygen-argon results was shown to be within the limits of experimental error if allowance is made for observed extra absorption, which is believed to be due to the presence of excited argon atoms at high temperature.