“…Assemblies of mercury jets have also been reported by Fogel et al (1956), Dawton (1961), and Bethge and Gunther (1964), though these investigations were aimed primarily at the production of negative ions. A water vapor jet has been built by Roos et al, (1965), and jets of carbon dioxide, nitrogen, and argon have been tested by Borovik et al (1964) and BusOl et al (1965). Charge exchange work on heavy ions has been carried out by the Heidelberg group Ill -12 with jets of mercury and carbon dioxide (Franzke et al 1967(Franzke et al , 1971(Franzke et al , and 1972.…”