Extraction and focusing of intense ion beams from a magnetically insulated diode

Abstract
A magnetically insulated diode has been used to produce cylindrically converging intense proton beams. By providing electron neutralization along field lines, the beams can be propagated across the magnetic field to within 1 cm of the axis. Proton currents up to 5 kA have been propagated to achieve current densities up to 70 A/cm2. Divergences less than 3° have been achieved with new plasma anode designs. Calculations are presented on the extrapolation of magnetic diodes to achieve power densities needed for ion‐beam pellet‐fusion breakeven.