Precision spectroscopy and comprehensive analysis of perturbations in the A¹∏(v = 0) state of ¹³C¹⁸O

ABSTRACT

We have reinvestigated the A level of ¹³C¹⁸O using new high-resolution spectra obtained via multi-photon laser excitation as well as with synchrotron-based Fourier-transform absorption spectroscopy of the A, e, d, a, and a bands. In addition, Fourier-transform emission spectroscopy in the visible range is performed on the band. Spectra of the B band are measured in order to tie information from the latter emission data to the level structure of A. The high pressures in the absorption cell at the synchrotron and the high temperatures in the emission discharge permitted monitoring of high rotational quantum levels in A up to J=43. All information, in total over 900 spectral lines, was included in an effective Hamiltonian analysis of the Alevels that are directly perturbed by the e, d, a, D, I close-lying levels and the e, d, a remote levels, as well being indirectly influenced by the a state. The influence of 9 further perturber levels and their interactions was investigated and are not significant for reproducing the present experimental data. This analysis leads to a much improved description in terms of molecular constants and interaction parameters, compared to previous studies of the same energy region for other CO isotopologues.

GRAPHICAL ABSTRACT

Keywords:

• Laser spectroscopy
• Fourier-transform spectroscopy
• carbon monoxide
• isotopologues
• deperturbation analysis

Acknowledgements

The authors are grateful to the general and technical staff of SOLEIL for providing beam time under projects no. 20120653 and no. 20160118.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

RH thanks LASERLAB-EUROPE for support of this research (Grants EUH2020-RIP-654148 and EC's- SPF-284464) as well as European Regional Development Fund and the Polish state budget within the framework of the Carpathian Regional Operational Programme (RPPK.01.03.00-18-001/10) through the funding of the Center for Innovation and Transfer of Natural Science and Engineering Knowledge of the University of Rzeszów. AH acknowledges support from the Postdoctoral Fellowship program of PSL Research University Paris and NASA Postdoctoral Program. WU acknowledges financial support from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 670168). RWF is grateful to the US National Science Foundation (Grant CHE-1361865).