Measurement of the magnetic field distribution in a magnetically insulated diode with external magnetic field

The current density of intense pulsed ion beam can be adjusted by modulating the magnetic field of a magnetically insulated diode, and this makes the magnetic field distribution vital to the performance of the diode. In this work, the magnetic field of a magnetically insulated diode was measured by a magnetic probe composed of one pair of perpendicular induction coils. As revealed by the measurement, the minimum magnetic induction intensity is reached near the outer cathode, while the value increases monotonically with approach to the inner cathode. The nonuniform emission of anode was discussed with account for this distribution. It is also demonstrated that the magnetic field distribution can be affected by the additional magnetic field induced by the eddy current in the anode. The method to improve the efficiency of the diode and optimization of accelerator performance was discussed reasonably.