NEW POSSIBLE LASER MEDIA IN THE UV AND XUV IN HIGH-CURRENT HEAVY-ION BEAM-INDUCED PLASMAS

Mixtures of rare gases with alkali-metal vapour were excited by a high power argon ion beam in a windowless gas target system. Narrow emissi on continua were observed in the vacuum ultraviolet region between 60 and 200 nm. The observed emission was assigned to the decay of a new c lass of excited ionic molecules Rg+A formed by the combination of a ra re gas ion Rg+ with an alkali atom A. These excimer-like ions are of g reat interest for possible short-wavelength lasers, because the ground state consisting of a rare gas atom and an alkali ion is only weakly bound. The observed decay energies and fine structure splittings agree well with the prediction of calculations. A summary of previous resul ts is presented.