Analysis of the CRDS spectrum of ~(18)O _3 between 6950 and 7125cm ~(-1)

摘要

The absorption spectrum of the ~(18)O _3 isotopologue of ozone was recorded by CW-Cavity Ring Down Spectroscopy in the 6950-7125cm ~(-1) region. The typical noise equivalent absorption of the recordings is α _(min) ≈1×10 ~(-10)cm ~(-1). The spectrum is dominated by three very weak bands: 3ν _1+5ν _3 near 7009cm ~(-1) and the ν _2+7ν _3 and 4ν _2+5ν _3 interacting bands near 7100cm ~(-1). In total 260, 206 and 133 transitions were assigned for the 3ν _1+5ν _3, ν _2+7ν _3 and 4ν _2+5ν _3 bands, respectively. The line positions of the 3ν _1+5ν _3 band were modelled using an effective Hamiltonian (EH) model involving two dark states - (601) and (252) - in interaction with the (305) bright state. The EH model developed for the ν _2+7ν _3 and 4ν _2+5ν _3 bands involves only the (017) and (045) interacting bright states. Line positions could be reproduced with rms deviations on the order of 0.01cm ~(-1) and the dipole transition moment parameters were determined for the three observed bands. The obtained set of parameters and the experimentally determined energy levels were used to generate a list of 984 transitions of the three bands which is provided as Supplementary Material.