A study of the absolute infrared intensity of ngr;3, absorption from vibrationally excited molecules, and the vapor pressure of UF6thinsp;

摘要

Results are presented from laser diode studies of ngr;3transition of UF6in the 16 mgr;m region using a very long optical path absorption cell. The ngr;3Qhyphen;branch and several individual rotational transitions have been recorded in the temperature range between 165 and 295 K. From the ngr;3band contour analysis and the line intensity measurements, the vibrational band strength of the ngr;3transition,S0V=710plusmn;120 kmthinsp;moleminus;1, was obtained. From absorption measurements of a UF6sample in the cooled cell at pressures from 10minus;3to 10minus;5Torr, the vapor pressure curve of UF6was extended to the temperature range down to 165 K. A new technique is described allowing us to obtain diode laser rsquo;rsquo;surveyrsquo;rsquo; spectra over a range of 25 cmminus;1by rsquo;rsquo;mode scans.rsquo;rsquo; This technique allows us to measure the changes in the band shape of ngr;3as a function of temperature, and thus learn something about rsquo;rsquo;hot bandrsquo;rsquo; absorption from vibrationally excited molecules.