Development of an applied-magnetic-field diode for ion-beam-transport experiments

Summary form only given. An applied-magnetic-field ion diode (ABD) is being developed to study the transport of intense ion beams for light-ion inertial confinement fusion. Initially, the beam from this diode will be used to test the concept of self-pinched transport (SPT). The design goal is diode operation at 1.5 MV and 250-kA total current on the Gamble II generator at NRL. This goal is based on Gamble II experiments with a 50-cm/sup 2/ area ABD, and a grooved-anode flashover source which produced 55 kA at 1.25 MV and V/sub crit//V/spl ap/2.5. Also, a measured beam divergence of 25 mrad is used in this design. A diode with an anode area of 160 cm/sup 2/ is required. To match this diode to Gamble II, a parallel electron-beam load upstream of the ABD is used to clamp the voltage, producing a more monoenergetic beam with improved focusing. For SPT experiments, the beam is extracted from the diode and focused into a transport channel. The ATHETA code (Sandia National Laboratories) is used to calculate B-field configurations in the diode and ion-beam trajectories.