To date only a few laser transitions in very short wave length of vacuum ultraviolet (VUV) or soft X-ray region have been demonstrated. The main thrust of the research is to establish experimentally controllable criteria to ascertain the feasibility of XUV and VUV lasers. VUV transitions in the ionic alkali halide excimers, with potential high output power, and XUV transitions in doubly excited alkali atoms, promising the generation of coherent radiation below 100 nm are being studied. For both systems pumping of the upper laser levels by collisional energy transfer from excited metastable rare gas atoms is being investigated. A second objective is the investigation of collisional energy transfer processes from excited metastable rare gas atoms to inner shell excited alkali atoms and ionic alkali halide molecules. Furthermore, the decay of highly excited alkali atoms and alkali halide molecules is being studied.
