Ba ii fluorescence from barium atoms resonantly photoionized by 584-Å radiation

The first reported study of a fluorescence spectrum of a metal vapor resonantly excited by vacuum-ultraviolet radiation has been made in Ba ii. Seven Ba ii fluorescent transitions have been identified for Ba vapor excited by 584-Å radiation. The intensities of these transitions are consistent with the population distribution of excited Ba ii observed by using photoelectron spectroscopy. No detectable Ba ii fluorescence was observed when 736–742-Å excitation was used.