LOW-ENERGY VACUUM-ARC ION-SOURCE

We have developed a version of vacuum arc ion source that.produces a m etal ion beam with energy of order 1 keV. The ion beam extractor is a three-grid, multiaperture configuration with a low accel-decel ratio s o that ions are extracted from the plasma at a relatively high energy and then decelerated to the desired net beam energy. We have tentative ly given this ion source the name leva, for low energy vacuum arc ion source. The leva source is cylindrical in shape with diameter about 6 cm and length about 16 cm and is located completely within the vacuum system; it is constructed from metal and alumina only and can be baked . We have operated it at net extraction voltages in the range 0.5-10 k V and produced a titanium ion beam current of up to 120 mA. Here we de scribe the source construction details and its performance.