Laser and Fourier transform spectroscopy of KCa

TL;DR

This study combines Fourier transform and laser spectroscopy to analyze the KCa molecule's electronic states, providing detailed energy level data and potential energy curves for ground and excited states.

Contribution

It presents new high-resolution spectral data and derived molecular parameters for KCa, including Dunham coefficients and potential energy curves, enhancing understanding of this molecule's structure.

Findings

Detailed vibrational and rotational energy levels for KCa's ground and excited states.

Derived Dunham coefficients and spin-rotation parameters.

Constructed potential energy curves for both states.

Abstract

KCa was produced in a heatpipe oven and its thermal emission spectrum around 8900 cm$^{-1}$ was recorded by a high resolution Fourier transform spectrometer. In addition, many selected transitions of this spectrum between deeply bound vibrational levels of the $\mathrm{X}(1)^2\Sigma^+$ and $(2)^2\Sigma^+$ states were studied using laser excitation to facilitate the assignment of the lines. The ground state is described for $v^{\prime\prime} =$ 0 - 5 and the $(2)^2\Sigma^+$ state for $v^{\prime} =0$ - 8 with rotational levels up to 175. For both states, Dunham coefficients, spin-rotation parameters and potential energy curves are derived.