Quenching of electronically excited barium atoms, Ba(5d 3D J)

The lowest optically metastable excited state of barium, Ba(5d 3DJ), was populated by laser excitation of the 6p 1P01←6s 1S0 (λ=553.5 nm) transition followed by the spontaneous emission 6p 1P01→5d 3DJ (λ∼1130 nm). No evidence for the normally spin allowed transition 6p 1P01 →5d 1D2 (λ=1500 nm) was obtained. The deactivation of Ba (5d3DJ) by Ba (6s 1S0) is extremely efficient proceeding with a thermal cross section of 1.3±0.1 nm2 at ?730 K. This is in sensible accord with recent calculations of Ba2 potential curves.