Electronic states of Bi₂studied by laser-excited fluorescence

Laser-excited fluorescence spectra of Bi2 have been studied both by high-resolution Fourier transform spectrometry and by conventional grating spectroscopy. The line Ar+ 5145 AA excites extensive series in the system A Ou+-X1 Sigma g1. Ultraviolet lines of both argon-ion and krypton-ion lasers excite a new transition, V Ou+-X1 Sigma g+, and V Ou+; radiates both to X1 Sigma g+ and to a new state B'Og+. Levels of the ground state X1 Sigma g+ have been characterised in the range 0<or= nu <or=105. Evidence is given to show that B' is the 0g+ component of the 5 Sigma g+ state formed from ground-state atoms, Bi(4S32/o)+Bi(4S32/o). Constants for the new states are given.