Designing an electron gun for an efficient Mobile Ionospheric Heating Source

The University of Maryland is developing a high power Radio Frequency (RF) source for use as a Mobile Ionospheric Heating Source (MIHS). This prototype will utilize Inductive Output Tube (IOT) technology operating in class-D amplifier mode using a grid-less electron gun. This paper will present a novel grid-less electron gun design, capable of producing annular beams with high currents in the range of 15A that utilizes a mod-anode to bring the gun from cut-off to saturation.