15min:

HARSHAL GUPTA, SHANSHAN YU, BRIAN J. DROUIN AND CHARLES E. MILLER, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109; HOLGER S. P. MÜLLER, I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, Köln, Germany .

Submillimeter-wave rotational spectra of O¹⁸O and ¹⁸O₂ in the a¹ _g state have been detected in a new static discharge cell useful for studying rare isotopologues of transient molecules. Rotational transition frequencies of both species have been measured through 1.6 THz, to better than 1 part in 10⁷, allowing precise determination of molecular constants. The first measurements with our static discharge cell provide a check on the isotopic predictions in the a¹ _g state.