Light ion beam production by an applied Br magnetically insulated annular diode

We tested a Br magnetically insulated annular diode for 50 nsec-pulse ion beam production. The ratio of ion to electron current was measured to be about 40 %, which agreed with the ratio of an electron to ion residence time in the diode gap. There was found apparent correlation between patterns of cathode electron bombardment on the anode and of ion beams through the cathode, which implied that the cathode electron bombardment played an important role in production of the anode plasma. It was also demonstrated that a specially treated plastic plane anode worked as well as the usual anode with buried copper pins. The treatment is to expose previously the anode surface to intense electron bombardment under no magnetic insulation before ion beam production.