Space and time evolution of high-power microwave breakdown on the atmosphere side of the dielectric surface

摘要

The high-power microwave breakdown on the atmosphere side of the dielectric surface leads to the formation of the thin plasma layer. A two-dimensional model coupling Maxwell's equations with quasi-neutral plasma fluid equations is used to study the breakdown evolution. We concentrate on the breakdown caused by the incident electric field parallel to the dielectric surface. The results show that the electric field enhancement at the tips of plasmoid in the direction parallel to the dielectric surface accelerates the propagation of the plasma front, while the propagation speed in the perpendicular direction decreases in time since the upstream plasma collapses the local electric field. The difference between the two speeds is responsible for the formation of the thin plasma layer. The effect of air pressure on the breakdown evolution is discussed. The breakdown delay time from simulations as a function of pressure shows the same trend as the experiment.