Performance tests of extraction diodes with cryogenic anode

Performance of magnetically insulated diodes with externally applied Br radial field was tested experimentally. Beam generation and the propagation have been studied in detail as a function of the insulating magnetic field, anode dielectric materials, and the structure of anode surface. It was clarified that Bz component of the field degraded the diode efficiency and the return field in drift region was not preferable for beam propagation. Various types of f1ashover anodes were tested and it was confirmed that ion beams produced from cryogenic ion sources were not at all inferior to the ones from conventional anode materials. The effects of detailed anode surface geometry were also examined.