The 3-0 Quadrupole Band in H2 by Cavity Ring-Down Spectroscopy
D C. Robie, Joseph T. Hodges
Several lines in the S and Q branches (including the previously unobserved Q32 and Q33 lines) of the 3-0 quadrupole band of H2 have been detected by cavity ring-down spectroscopy using a multimode laser with a long cavity. The noise equivalent absorption coefficient was as low as 4 10-10 /cm Hz, permitting signal-to-noise ratios up to 1000. Peak areas were measured at densities between 0.1 and 2.8 amagats at 296 K. Observed linestrengths in the S branch are consistent with earlier measurements, and about 10% below theoretical calculations. Observed linestrengths in the Q branch are about 30% below theory. Evidence is presented that collision-induced absorption is significant in these conditions.PACS numbers: 33.20.Kf, 33.70.Fd, 96.35.Hv
Journal of Chemical Physics
cavity ring-down, hydrogen, line strength, quadrupole moment
and Hodges, J.
The 3-0 Quadrupole Band in H2 by Cavity Ring-Down Spectroscopy, Journal of Chemical Physics
(Accessed November 28, 2023)