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Published November 26, 2009 | public
Journal Article

Experimental Line Parameters of the b^(1)Σ^(+)_g ← X^(3)Σ^(-)_g Band of Oxygen Isotopologues at 760 nm Using Frequency-Stabilized Cavity Ring-Down Spectroscopy


Positions, intensities, self-broadened widths, and collisional narrowing coefficients of the oxygen isotopologues ^(16)O^(18)O, ^(16)O^(17)O, ^(17)O^(18)O, and ^(18)O^(18)O have been measured for the b^(1)Σg + ← X^(3)Σg − (0,0) band using frequency-stabilized cavity ring-down spectroscopy. Line positions of 156 P-branch transitions were referenced against the hyperfine components of the ^(39)K D_1 (4s ^(2)S_(1/2) → 4p ^(2)P_(1/2)) and D_2 (4s ^(2)S_(1/2) → 4p ^(2)P_(3/2)) transitions, yielding precisions of ~0.00005 cm^(−1) and absolute accuracies of 0.00030 cm^(−1) or better. New excited b^(1)Σg + state molecular constants are reported for all four isotopologues. The measured line intensities of the ^(16)O^(18)O isotopologue are within 2% of the values currently assumed in molecular databases. However, the line intensities of the ^(16)O^(17)O isotopologue show a systematic, J-dependent offset between our results and the databases. Self-broadening half-widths for the various isotopologues are internally consistent to within 2%. This is the first comprehensive study of the line intensities and shapes for the ^(17)O^(18)O or ^(18)O_2 isotopologues of the b^(1)Σg + ← X^(3)Σg − (0,0) band of O_2. The ^(16)O_2, ^(16)O^(18)O, and ^(16)O^(17)O line parameters for the oxygen A-band have been extensively revised in the HITRAN 2008 database using results from the present study.

Additional Information

© 2009 American Chemical Society. Received: February 6, 2009; Revised Manuscript Received: May 22, 2009. Publication Date (Web): July 8, 2009. Part of the research described in this paper was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with The National Aeronautics and Space Administration (NASA). Additional support was provided by the Orbiting Carbon Observatory (OCO) project, a NASA Earth System Science Pathfinder (ESSP) mission; the NASA Upper Atmospheric Research Program grant NNG06GD88G; and the NIST Office of Microelectronics Programs. Laurence Y. Yeung would like to acknowledge the support of the Davidow Graduate Fellowship in Environmental Science. David A. Long acknowledges the support of the National Defense Science and Engineering Graduate Fellowship. Daniel K. Havey received support from the National Research Council as a postdoctoral fellow at NIST. Finally, we would like to acknowledge the assistance of Dr. Mona Shahgholi in performing the mass spectral analyses of our enriched gas sample.

Additional details

August 19, 2023
October 19, 2023