Precision spectroscopy and comprehensive analysis of perturbations in the \(A\,{}^1\Pi(v=0\)) state of \({}^{\rm 13}\)C\({}^{\rm 18}\)O

• Published in: arXiv.org 2018-08
• Main Authors: Hakalla, R, Trivikram, T M, Heays, A N, Salumbides, E J, de Oliveira, N, Field, R W, Ubachs, W
• Format: Article
• Language: English
• Subjects: Fourier transforms; Interaction parameters; Line spectra; Spectrum analysis
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1808.02476

We have reinvestigated the A$^1\Pi$$(v=0)\( level of \)^{13}\(C\)^{18}\(O\ using new high-resolution spectra obtained via multi-photon laser excitation as well as with synchrotron-based Fourier-transform absorption spectroscopy of the A\)^1\Pi -\textrm{X}^1\Sigma^+$$(0, 0)\(, e\)^3\Sigma^--\textrm{X}^1\Sigma^+$$(1, 0)\(, d\)^3\Delta-\textrm{X}^1\Sigma^+$$(4, 0)\(, a\)'^3\Sigma^+-\textrm{X}^1\Sigma^+$$(9, 0)\(, and \atX\)(11, 0)\( bands. In addition, Fourier-transform emission spectroscopy in the visible range is performed on the \){\rm B}^1\Sigma^+-{\rm A}^1\Pi$$(0, 0)\( band. Spectra of the \BX\)(0, 0)\( band are measured in order to tie information from the latter emission data to the level structure of A\)^1\Pi$$(v=0)\(. The high pressures in the absorption cell at the synchrotron and the high temperatures in the emission discharge permitted monitoring of high rotational quantum levels in A\)^1\Pi$$(v=0)\( up to \)J=43\(. All information, in total over 900 spectral lines, was included in an effective-Hamiltonian analysis of the A\)^1\Pi(v=0, J)\( levels that are directly perturbed by the e\)\,^3\Sigma^-$$(v=1)\(, d\)^3\!\Delta$$(v=4)\(, a\)'^3\Sigma^+$$(v=9)\(, d\)^3\!\Delta$$(v=0)\(, I\)\,^1\Sigma^-$$(v=0, 1)\( close-lying levels and the e\)\,^3\Sigma^-$$(v=0,2)\(, d\)^3\!\Delta$$(v=3,5)\(, a\)'^3\Sigma^+$$(v=8,10)\( remote levels, as well being indirectly influenced by the a\)^3\Pi$$(v=10, 11)$ state. The influence of nine 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.