A pulsed vacuum arc ion source with a pure boron cathode

The report presents experimental results on a pulsed vacuum arc ion source with an elemental boron cathode. Boron is a semiconductor having a high specific resistance (similar to 1.8 MOhmxcm) under normal conditions and is difficult to sputter and evaporate [1]. Therefore, for arc ignition with pure boron, it is required to preheat the cathode up to 1000 degrees C. We have designed a high-temperature cathodic unit which uses a special arc triggering technique, provides cathodic arc operation with pure boron, and allows one to decrease the cathode temperature down to 600 degrees C. For an arc current of 100 A with a duration of 100-300 us, the 450-mA beam consists of boron ions in singly and doubly ionized states.