PNNL

Abstract

N2-broadening and N2-pressure-induced shift coefficients; and the temperature dependence exponent of the N2-broadening and the temperature dependent coefficients of N2-pressure-induced shifts have been measured for transitions in the v2 band of HCN from analysis of high-resolution absorption spectra recorded with two different Fourier transform spectrometers. A total of 34 laboratory spectra recorded at 0.002-0.005 cm-1 resolution and at temperatures ranging from 211 to 300 K were used in the determination of various spectral line parameters. A multispectrum nonlinear least squares curve fitting technique employing a modified Voigt line profile including speed dependence was used in the P- and R-branch measurements. In analyzing the Q branch transitions, the off-diagonal relaxation matrix element coefficients were included in analysis to fit the data. Present results are compared to previous measurements reported in the literature.