Kinetic Simulation of Plasma Sheath Relevant to Cross-Field Diodes

It is critical to understand the formation and propagation of plasma near electrodes to improve the performance of cross-field devices, such as high-power microwaves. In order to investigate the effects of electron emission from the electrodes and magnetic field, a particle-in-cell (PIC) simulation is developed to study the plasma-wall interactions relevant to cross-field diodes. This 1D model is verified and benchmarked with previous work of plasma sheath with and without an applied, oblique magnetic field [1] , [2] . The normalized, electrostatic model is then employed to investigate the effects of secondary electron emission (SEE) and applied magnetic field on the steady-state potential structure near a dielectric wall and in the pre-sheath region. This includes studying the transition to the space-charge limited regime as SEE increases, which leads to the formation of inverse sheaths or virtual cathodes, where the latter may be relevant to the performance of cross-field diodes [3] , [4] .