Narrowing and Broadening Parameters for H2O Lines in the ν2 Band Perturbed by Nitrogen from Fourier Transform and Tunable Diode Laser Spectroscopy

Dicke-narrowed spectral line shapes of CO in Ar: Experimental results and a revised interpretation

“…It has since been well established that a meaningful study of Dicke narrowing in CO-Ar, HF-Ar, and similar systems must account for speed dependence (see for example, [4,38,42,43,49,51,52]), and we therefore limit our discussion to speed-dependent analyses. To the best of our knowledge, [1][2][3][4][5][6][7]16,31,33,[36][37][38][39][40][41][42][43]49,[51][52][53][54][55][56][57][58][59][60][61][62] are the only studies that use a speed-dependent, Dicke-narrowed line shape model to analyze experimental data.…”

“…It is sometimes referred to as the (effective) velocity-changing collision rate. By convention, the narrowing parameter z is defined as m/x D , where x D = k(2k B T/m a ) 1/2 is the Doppler half width at e À1 intensity for wavevector k, Boltzmann constant k B , and temperature T. A common [2][3][4][5][36][37][38][39][40][41][42][43][44] approach to analyzing Dicke-narrowed line shapes is to fit for m and compare the result to the dynamic friction coefficient, m diff , which is obtained from the mass diffusion constant D by…”

An accurate comparison of lineshape models on H2O lines in the spectral region around 3μm

“…Eng et al [23] were first to observe strong effect of Dicke narrowing for lines in H 2 O m 2 band transitions between states of high rotational energy, perturbed by Xe and Ar. Claveau et al [24,25] also investigated collisional narrowing in m 2 band lines in a presence of different molecular and atomic perturbers. Papers related to collisional narrowing of H 2 O and other molecules can be found in a paper by Claveau et al [24] and by Henry et al [26].…”

Measurement of the coefficients of H2O absorption line shifts by intracavity laser spectroscopy

“…For example, mass measurements of half-widths and shifts for more than 1000 lines of the ν 2 band induced by Н 2 О, N 2 , and air pressure were performed in [2,3]. In [4,5], the line shapes of the ν 2 band of water vapor broadened by He, Ne, Ar, Kr, and N 2 were investigated using Fourier spectrometers. Intracavity (IC) laser spectroscopy with some changes in the measurement procedure and improvement of recording equipment opens up fresh opportunities in this field.…”

“…Thus, the shift coefficients carry important information on the forces of molecular interaction including the dependence of the coefficients on atomic oscillations. Therefore, recently, most attention has been concentrated on measurements of this parameter of pressure-induced line shapes of different buffer gases [2][3][4][5].…”