Absorption by pure NH₃ and NH₃-H₂ mixtures in the 5 μm window region

Absorption by pure NH₃ and NH₃-H₂ mixtures in the 5 μm transparency region was studied at room temperature using two different set-ups. Measurements were made for various density conditions in order to deduce pressure normalized absorption coefficients due to line-wing contributions. The results obtained from the two experiments are in good agreement and demonstrate that the NH₃ line wings are significantly sub-Lorentzian, particularly when broadened by H₂. Empirical corrective line-shape factors χ are proposed for NH₃-NH₃ and NH₃-H₂ collisions whose use leads to satisfactory agreement with experiments and that should be useful for the prediction of Jovian spectra.