The B̃ 4Σ−uX̃ 4Σ−g electronic spectrum of C+2

Abstract
The B̃ 4ΣuX̃ 4Σg electronic transition of C+2 has been studied in the gas phase by laser excitation spectroscopy. The rotational analysis of ten vibronic bands of 12C+2(v’,v‘≤3) and seven of 13C+2(v’,v‘≤2) has been carried out. The spectroscopic constants Te, Be, αe, ωe, ωexe are obtained for 12C+2 and 13C+2 in the X̃ 4Σg and B̃ 4Σu states. The lifetimes of C+2 in selected levels of the B̃ 4Σu state have been measured and the oscillator strength f0–0 =0.023(3) is derived.