In the wavelength range 280-700 nm the authors have observed more than 60 resonances in the production of Ba2+ from neutral Ba. All the strong resonances can be associated with Ba+ transitions originating in the 6s12/, 5dj or 6pj states. The production of Ba 2+ is highest for the wavelength range 450-650 nm, where numerous two- and three-photon resonances occur in the multiphoton ionisation of Ba +.
