DETERMINATION OF BROADENING COEFFICIENTS AND INTENSITIES FOR OVERLAPPING SPECTRAL-LINES WITH APPLICATION TO THE (Q)R(3,K) LINES IN THE NU(3) BAND OF (CH3CL)-CL-35

We have developed a method of extracting individual line parameters from overlapping absorption spectra recorded with a tunable diode-laser spectrometer. Assuming Voigt profiles for the individual lines, the overall absorption is expressed as the SUM of the absorption coefficients of the recorded lines plus a small contribution due to neighboring lines. The computational procedure has been applied to the four (Q)R (3,K) lines, self-broadened and broadened by N2, O2, Ar and He, in the nu3 band of (CH3Cl)-Cl-35 at 736.3 cm-1. The intensities and collision-broadened widths are found to be linear functions of the broadener pressures, which implies negligible line-mixing effects between the K components. For all of the perturbers considered the broadening coefficients of the (Q)R (3,K) lines decrease significantly as K increases, in agreement with theoretical results.