5314027772

POSTER SESSION. H28

LOW TEMPERATURĘ MEASUREMENTS OF SHIFT AND BROAD-ENING OF CO AND C0₂ LINES WITH N₂, 0₂ AND ARGON AS FOREIGN GASES

T. DRASCHER, U. FUCHS_t N. SCHMUCKER, T. GIESEN, R.SCHIEDER, AND G. WINNEWISSER, /. Phys. Inst., Univer-

sity of Cologne, Ziilpicher Str. 77, 50937 Koln.

Using a freąuency stahilized diodę laser spectrometer, the ternperature dependence of the pressure induced shift and broadening of the P(2) linę of CO at 2135 cm^-1 has been measured. N₂, 0₂ and argon were used as foreign gases. In the case of linę broadening, the temperaturę dependence is quite well reproduced by an expouential relation, b[T) = &(/b)(T/To)"ⁿ. For all foreign gases, the exponent n has been obtained and a value for air has been calculated froin the weighted mean values of N₂ and 0₂. Within the error limits, tłie magnitudes of all shifts decrease with inereasing temperaturę but no exponential behavior of the shift versus ternperature is observed. The linę broadening and shift for CO by Ar and the broadening of CO by N₂ have been compared to calculations from the semi-classical theory of Robert and Bonamy [1] . Agreement has bi»en achicved for the linę broadeuing, while for all temperatures the calculated shifts are hirger than the measured values.

For all measurements a freąuency stabilized tunable infrared diodę laser spectrometer has been used to achieve high freąuency accuracy. The scnsitivity of the spectrometer has been improvcd significantly by use of a multiple reflection celi with a base length of lm and an absorption length of about 135m. Tlie celi can be cooled down to temperatures in the rangę of 150K. Spectra were recorded at 5 to 7 different temperatures and at different pressures for every foreign gas. Measurements of C0₂ lines in the same ternperature rauges are in progress and will be presented as well.

Bonamy, D. Robert, C. Boulet, ./. Quant. Specłrosc. Radiat Transfer 31. 23-34 (1984)