Multiphoton double ionisation of Ba from 280 to 700 nm

In the wavelength range 280-700 nm the authors have observed more than 60 resonances in the production of Ba 2+ from neutral Ba. All the strong resonances can be associated with Ba + transitions originating in the 6s 1 2/, 5dj or 6p j 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 + .