Noble gas induced line-shift and line-broadening in the nu(2) band of H2S

The rotational dependence of pressure-induced shift and broadening of H2S a bsorption lines in the nu(2) band due to collisions between H2S molecules a nd atoms of noble gases (He, Ne, Ar, Kr, and Xe) were studied in the spectr al region between 1050 and 1325 cm(-1). The measurements were carried out u sing an improved pulse-driven diode laser spectrometer, allowing a new tuni ng technique of the diode laser, The parameters of this set-up will be comp ared to the parameters of the previously used spectrometer. The data concer ning collisional broadening and shift coefficients, gamma and delta, respec tively, and their dependencies on the rotational quantum number, J ", mass, and the polarizability, alpha, of the noble gases are presented for 14 P-b ranch transitions (3 less than or equal to J " less than or equal to 8), se ven Q-branch transitions (7 less than or equal to J " less than or equal to 10), and 18 R-branch transitions (2 less than or equal to J " less than or equal to 11). The broad -ening coefficients were determined with an accura cy of 1% (3.5 x 10(-4) cm(-1)/atm) and shift coefficients were determined w ith an uncertainty of less than 5 x 10(-4) cm(-1)/atm for the majority of l ines and broadening gases. The qualitative explanation of experimental resu lts was made based on the models and interactions also used in the ATC and CRB theories, respectively. (C) 2000 Elsevier Science B.V. All rights reser ved.