Abstract

Simplified equations are developed for computing the spectral emissivity of the carbon dioxide 2.7-μ band. The harmonic oscillator model is assumed in computing band intensities, but anharmonicity is considered in computing the spectral distribution of emitted radiation. Simplifying assumptions are made to account for the effects of Fermi resonance. Calculated values of $\overline{S}/d$ are presented for temperatures ranging from 300° to 3000°K, from which emissivities may be readily computed for a given optical path in the weak-line approximation. Calculated values of emissivity are also presented for temperatures ranging from 300° to 1500°K, for various optical depths, for the case of a pure Doppler line shape as well as for the weak-line approximation. Calculated values of $2{{\alpha }_0}^{\frac{1}{2}}{\overline{S}}^{\frac{1}{2}}/d$ are presented for temperatures ranging from 300° to 1200°K, from which emissivities may be computed in the strong-line approximation. The weak-line approximation is shown to be in reasonable agreement with published experimental data for 1200° to 1500°K. An explicit formula for the temperature variation of the integrated band intensity is shown to be in agreement with experimental data from 300° to 3000°K.

© 1964 Optical Society of America

Infrared Emissivity of Carbon Dioxide (4.3-μ Band)*

W. Malkmus
J. Opt. Soc. Am. 53(8) 951-961 (1963)

Emissivity of Carbon Dioxide at 4.3 μ

William O. Davies
J. Opt. Soc. Am. 54(4) 467-471 (1964)

Spectral Emissivities and Integrated Intensities of the 2.7- μ CO₂ Band between 1200° and 1800°K*

C. C. Ferriso and C. B. Ludwig
J. Opt. Soc. Am. 54(5) 657-662 (1964)

Measurements of Infrared Spectral Emissivities of Hot Carbon Dioxide in the 4.3-μ Region*

Richard H. Tourin
J. Opt. Soc. Am. 51(2) 175-183 (1961)

High-Temperature Spectral Emissivities of H₂O–CO₂ Mixtures in the 2.7-μ Region

C. C. Ferriso and C. B. Ludwig
Appl. Opt. 3(12) 1435-1443 (1964)