Theoretical study on the air breakdown by perpendicularly intersecting high-power microwave

Abstract

Air breakdown by perpendicularly intersecting high-power microwave (HPM) is investigated by numerical solution of fluid-based plasmas equations coupled with the Maxwell equations. For two coherently intersecting HPM beams, collisional cascade breakdown occurs only if the initial free electron appears or arrives at the strong electric field, where the electron can be accelerated. At the initial stage of discharge, the filamentary plasma moves along the strong field and forms plasma-filament band. When the plasma-filament band grows long enough, in the vicinity of which the two HPM beams were separated due to its scattering and absorption by plasma. The new plasma-filament bands continue to appear as time increases. It is also found that, under the same condition, the plasma region produced by incoherent beams is smaller than that by coherent beams.