Formation process of negative ions in a magnetically insulated diode

The formation process of negative ions in a flashover diode plasma is investigated. A coaxial magnetically insulated diode, whose cathode can be cooled by liquid nitrogen or helium, is driven with a 5-Ohm/60nsec Blumlein line. Effects of voltage polarity, prepulse level, source materials, and surface structure of the electrode, on the diode characteristics are examined and the potentiality of the plasma as asource of intense negative ion beam is discussed.