Dual-current-feed magnetically insulated light-ion diode

A 3 x 1011-W modular magnetically insulated ion diode for inertial-confinement fusion studies is described. Power is supplied to the diode, which is centered in an elongated solenoidal B-field coil structure, by two self-magnetically insulated transmission lines. A circular ion beam is emitted preferentially from one surface of the curved anode plate and extracted through a 13-cm-diam virtual cathode and exposed B-field coils. The virtual cathode is formed by electrons which spiral along the B-field lines that conform to the anode surface. The ion beam converges onto a planar target, located 13-cm from the anode, through a 1-Torr air plume which allows space-charge and partial current neutralization of the beam. The beam is initially primarily composed of protons, but later carbon ions dominate. The proton beam has a divergence of 2.10 +- 0.30 and peak focused proton-current density of 60 kA/cm2