TY - JOUR

T1 - Line parameters and shapes of high clusters

T2 - R branch of the ν3 band of CH4 in He mixtures

AU - Grigoriev, I. M.

AU - Filippov, N. N.

AU - Tonkov, M. V.

AU - Champion, J. P.

AU - Gabard, T.

AU - Le Doucen, R.

PY - 2002/8/15

Y1 - 2002/8/15

N2 - The IR absorption spectra of CH4 in pure gas and in mixture with helium were studied in the region of ν3 band at higher J line clusters R(17)-R(22). The frequencies and intensities of rotation-vibration lines were estimated from the experimental spectra at Doppler shape conditions. The line frequencies and intensities were calculated and used for the attribution of overlapped lines in clusters. The calculated line intensities are close to the experimental values. The calculated frequency structure of the higher J manifolds are somewhat wider than the observed one. The shapes of helium-broadened line clusters were compared with those calculated accounting for line mixing. The relaxation matrix W, which is necessary in shape calculations, was constructed using semiclassical collision rate constants. The calculated shapes are in satisfactory accordance with the measured ones.

AB - The IR absorption spectra of CH4 in pure gas and in mixture with helium were studied in the region of ν3 band at higher J line clusters R(17)-R(22). The frequencies and intensities of rotation-vibration lines were estimated from the experimental spectra at Doppler shape conditions. The line frequencies and intensities were calculated and used for the attribution of overlapped lines in clusters. The calculated line intensities are close to the experimental values. The calculated frequency structure of the higher J manifolds are somewhat wider than the observed one. The shapes of helium-broadened line clusters were compared with those calculated accounting for line mixing. The relaxation matrix W, which is necessary in shape calculations, was constructed using semiclassical collision rate constants. The calculated shapes are in satisfactory accordance with the measured ones.

KW - Line mixing

KW - Line parameters

KW - Methane

KW - Vibration-rotation spectra

UR - http://www.scopus.com/inward/record.url?scp=0037102712&partnerID=8YFLogxK

U2 - 10.1016/S0022-4073(01)00263-1

DO - 10.1016/S0022-4073(01)00263-1

M3 - Article

AN - SCOPUS:0037102712

VL - 74

SP - 431

EP - 443

JO - Journal of Quantitative Spectroscopy and Radiative Transfer

JF - Journal of Quantitative Spectroscopy and Radiative Transfer

SN - 0022-4073

IS - 4

ER -