The origin of K 2, Rb 2 and Cs 2 triplet 1 3Π g−X 3Σ +u bands in discharge

Abstract

The absorption and emission spectra of potassium, rubidium and caesium low-pressure discharges have been studied at the far blue wings of resonance D2-lines. The observed diffuse bands were attributed to the 1 3Π g−X 3Σ + u transition. Experiments revealed the recombination 2P + 2S nature of these bands, and the corresponding rate coefficients were obtained. Energies of the higher excited states as well as the X 3Σ + u -state well depths for K 2, Rb 2 and Cs 2 molecules were estimated.