LAMBDA-SPLITTINGS AND LINE-INTENSITIES IN THE 2[-1 HOT-BAND OF NITRIC-OXIDE

Using Fourier transform spectra, A-splittings and absolute line intensities have been measured in the 2PI1/2-2PI1/2 and 2PI3/2-2PI3/2 allowed subbands of the vibrational 2 <-- 1 hot band of nitric oxide. To retrieve accurate results from the spectra, LAMBDA-doubling and hyperfine splittings were carefully taken into account. However, for most of the studied lines, it turned out that the components of the hyperfine structure are close enough so that they have no susceptible effects on the measured line parameters. Well-chosen cases illustrate the method of measurement. The observed LAMBDA-splittings have been compared with the values deduced from the transition wavenumbers available in the HITRAN database, and large discrepancies (up to 0.006 cm-1 for P(22.5)) appeared for the 2PI3/2-2PI3/2 subband. The measured line intensities led to the determination of the transition dipole moment as well as the Herman-Wallis coefficients for the studied hot band. Our measured intensities have been found to be larger than the HITRAN values by about 7%.