Collision-induced first overtone band of H2 in binary mixtures H2-N2 and H2-CO

Enhancement spectra of the collision-induced absorption (CIA) of H-2 in its first overtone region 7500-9500 cm(-1) in binary mixtures H-2-N-2 and H-2-CO were studied at 298 K for base densities of H-2 in the range 89-145 amagat and for partial densities of N-2 and CO in the range 19-392amagat. The observed spectra confirm that the isotropic overlap induction is absent in the 2-0 band of H-2 unlike in the CIA spectra of the fundamental band of H-2. Binary and ternary absorption coefficients were determined from the integrated absorption coefficients of the band. Enhancement absorption profiles of H-2-N-2 and H-2-CO consist of a total of 434 components of quadrupolar double transitions. Profile analysis of the spectra was carried out using Birnbaum-Cohen line shape function for the individual components of the band and characteristic line shape parameters were determined from the analysis. (C) 2005 Elsevier Ltd. All rights reserved.