N2, O2, H-2, AR AND HE BROADENING IN THE NU(1) BAND OF NH3

N2-, O2-, H-2-, Ar- and He-broadening coefficients and pressure shifts have been measured for Q- and R-branch transitions in the nu1 fundamental band of ammonia using a difference-frequency laser spectrometer. The J-K dependence of the broadening coefficients is much smaller than previously observed for self broadening of NH3. Semiclassical line broadening calculations for N2 broadening are in reasonable quantitative agreement with the data, but they also exaggerate the J-K dependence. Dicke narrowing is observed as strong deviations from Voigt profiles at intermediate pressures and provides estimates for optical diffusion constants which correlate well with the mass diffusion constants for NH3 in the various buffer gases.