Study of an ‘‘applied-Bθ ’’ magnetically insulated ion diode

Abstract
We report parametric studies of an ‘‘applied‐Bθ ’’ magnetically insulated ion diode, and the properties of the ion beam obtained from it. The typically 250‐keV ion beam extracted from this annular diode is focused by the diode field to a current density of up to 800 A/cm2 on axis 20 cm from the diode. Anomalously rapid dispersion of the beam beyond the focal region in vacuum is eliminated by puffing gas into the drift chamber.