RADIATIVE PROPERTIES OF HIGH TEMPERATURE GASES

A theory is presented to establish a rigorous basis for the computation of the number of ions in given quantum states, for a partially ionized gas in thermal equilibrium, in the low density limit. A calculation of the line contribution to the Planck mean absorption coefficient is made for nitrogen and oxygen and a measure of its significance to the Rosseland mean absorption coefficient is derived. Line broadening theories are discussed with respect to the calculation of absorption coefficients. A tabulation is presented of Debye lengths, ion sphere radii, occupation numbers and other parameters of significance to the radiative properties of nitrogen and oxygen. Measurements were made of absolute intensity of the radiation from shock heated nitrogen and oxygen in the temperature range of 8000 to 18,000 K. The wavelength range investigated is from 3500 to 5600 A. Transition probabilities for the N(+)2 First Negative System were inferred from the measurements. (Author)