15min:

THOMAS D. VARBERG, Department of Chemistry, Macalester College, St. Paul, MN 55105; FRED STROH, Institute for Stratospheric Chemistry, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany; KENNETH M. EVENSON, Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80303.

The absorption spectrum of the ¹⁴NO and ¹⁵NO isotopomers of nitric oxide in the far-infrared has been measured and analyzed. Pure rotational transitions up to J'' = 37-1/2 within the ²_1/2 and ²_3/2 spin components and several ²_3/2<-~ ²_1/2 fine-structure transitions were recorded within the ground vibrational state. A least-squares fit to these data combined with lambda-doubling transitions measured by previous workers has resulted in significant improvement in the accuracy of the rotational and fine-structure parameters of these two isotopomers. Improved values for the lambda-doubling and hyperfine constants will also be reported.