Investigation of the populations of excited states of barium atoms in a laser plasma

Laser-induced fluorescence was used in an investigation of the populations of the ground and excited (6s5d ³D₁ and ³D₂) states of Ba atoms in a plasma formed by laser ablation of Y–Ba–Cu–O target. A nonequilibrium velocity distribution of the atoms was detected. At large distances from the target about 4% of the atoms were in an excited state.