Millimeter-wave spectroscopy of Kr-CO and Xe-CO using a coaxial jet spectrometer

A new pulsed supersonic jet millimeter-wave spectrometer with coaxial propa gation of the molecular jet and millimeter-waves has been constructed. The coaxial configuration provides greater sensitivity which has been demonstra ted by observing b-type transitions of five isotopomers of Kr-(CO)-C-12-O-1 6 and seven isotopomers of Xe-(CO)-C-12-O-16. These results were analyzed t ogether with a-type transitions obtained by FTMW spectroscopy to determine improved rotational parameters for each isotopomer. The ground vibrational state K = 1 <-- 0 intervals have thus been precisely determined for Kr-CO a nd Xe-CO. (C) 2001 Academic Press.