High-Resolution Laser Photoacoustic Spectroscopy of OCS in the 12 000-13 000 cm(-1) Region

• Published in: Journal of molecular spectroscopy 1999-08, Vol.196 (2), p.265-273
• Main Authors: Tranchart, S, Hadj Bachir I, Huet, TR, Olafsson, A, Destombes, J, Naïm, S, Fayt, A
• Format: Article
• Language: English
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1999.7853

A spectrum of natural OCS has been recorded in the near-infrared region using the laser photoacoustic technique. The source is a titanium-sapphire laser pumped by an Ar(+) laser. The tunable 1.5 W beam was sent through the photoacoustic cell. This windowless longitudinal resonant cell was designed with two lambda/4 buffer volumes at both ends in order to reduce the noise and so to increase the sensitivity (alpha(min) approximately 10(-9) cm(-1)). The spectrum of OCS, at a pressure of 90 Torr, has been recorded in the regions 11 953-12 084, 12 829-12 890, and 12 998-13 001 cm(-1). In addition to the 00(0)6-00(0)0 band of (16)O(12)C(32)S recently identified by Ch. Hornberger, B. Boor, R. Stuber, W. Demtröder, S. Naïm, and A. Fayt, J. Mol. Spectrosc. 179, 237-245, 1996, new weaker bands have been observed: 04(0)5-00(0)0, 1 10(0)3-00(0)0, 10(0)6-00(0)0, 14(0)5-00(0)0, 02(0)6-00(0)0, and 01(1)6-01(1)0, and also the 00(0)6-00(0)0 band of (16)O(12)C(34)S. Effective state parameters are deduced from the band-by-band least-squares fits. The new data have also been introduced in the global analysis which takes into account the l-type resonance and the main anharmonic interactions and so allows a full understanding of the perturbations and the intensity transfers. Copyright 1999 Academic Press.