Diode-laser measurements and calculations of H2-broadening coefficients in the ν3 band of CH3D

✍ Scribed by Christophe Lerot; Jacques Walrand; Ghislain Blanquet; Jean-Pierre Bouanich; Muriel Lepère

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 176 KB
• Volume: 217
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1016/s0022-2852(02)00044-9

✦ Synopsis

Using a tunable diode-laser spectrometer, we have measured at room temperature the H 2 -broadening coefficients of 12 CH 3 D for 36 lines belonging to Q P and Q R branches in the m 3 parallel band. The recorded lines with J values ranging from 1 to 15 and K from 0 to 9 (K 6 J ) are located between 1196 and 1412 cm À1 . The H 2 -broadening coefficients were determined by fitting each spectral line with Voigt, Rautian, and Galatry profiles. They were also calculated on the basis of a semiclassical model of interacting linear molecules performed by considering in addition to the weak electrostatic contributions the atom-atom Lennard-Jones potential. The theoretical results are in reasonable agreement with the experimental data, except for high J transitions where they are overestimated and for K approaching or equal to J with J P 3 where they are underestimated. The latter discrepancy may be caused by the assumption to consider only DK ¼ 0 collision-induced transitions, associated with jDJ j transitions up to 4.