Impedance control of Applied-B ion diodes

Abstract
We present a device to control the rapidly decreasing impedance that has been observed with Applied‐B ion diodes. This device, which we call an impedance limiter, is a protrusion at the midplane of the anode. Its purpose is to reduce the electron space charge near the anode emission surface. Electromagnetic particle‐in‐cell simulations show that the impedance characteristics of an Applied‐B diode can be favorably modified by using this device. Preliminary experimental results on the particle beam fusion accelerator I for an Applied‐B ion diode using an impedance limiter show promise.