Generation and Transport of a Low-Energy Intense Ion Beam

This paper describes experiments on the formation and transport, in vacuum and plasma, of a low-energy (70-120 keV), high-intensity (10-30 A/cm/sup 2/), long-pulse (0.5-1/spl mu/s) H/sup +/ ion beam. The beam was generated in a magnetically insulated diode with an applied radial B-field and active hydrogen-puff plasma source at the anode. The combination of a ballistic focusing large area anode (250 cm/sup 2/) with a post-cathode toroidal magnetic lens and straight transport solenoid section provided beam transport to a distance of >1 m with an overall efficiency of /spl ges/ 50%. Two-dimensional single-particle computer simulations of the ion's trajectory in the lens/solenoid system supported optimization of the lens and solenoid parameters.