Investigation of line profiles in the v(2) band of H2S

Experiments with a three-channel lead salt diode laser spectrometer concern ing collisional effects for lines from the v(2) band of H2S were carried ou t in the laser spectroscopy group in Berlin. An improved experimental set-u p in comparison to the system as described in Sumpf et al. (J. Quant. Spect rosc. Radiat. Transfer 59 (1998) 99), e.g. liquid nitrogen cooling system, improved laser stability, multipass cells in both channels, allows us now t o detect the Dicke narrowing effect. To analyze the measured line profiles three types of contours, i.e. Voigt. Rautian-Sobel'man, and Galatry, were t aken into account. As result of this study Dicke narrowing was clearly obse rved for several lines. The most significant narrowing coefficient (31 +/- 4) 10 cm(-1) atm(-1) was found for the line 12(1.12) <-- 11(0.11) perturbed by Neon. Nevertheless, it was shown that for the lines under study the pre ssure broadening and shift coefficient's deviation due to not taking into a ccount Dicke narrowing, lies in the range of the uncertainties of the deter mination of the coefficients. (C) 1999 Elsevier Science B.V. All rights res erved.