垂直相交高功率微波大气击穿的理论研究

将描述电磁波的Maxwell方程组和简化的等离子体流体方程组耦合数值求解, 对垂直相交高功率微波电离大气产生等离子体的过程进行了模拟研究. 对于相干(同频)垂直相交高功率微波束, 只有当初始自由电子出现在(或到达)强场(干涉加强)处, 自由电子才会被加速并与本底气体发生碰撞电离, 在放电的开始阶段, 等离子体区域主要沿着强场区运动, 并逐渐形成一个由分立的丝状等离子体组成的带状区域. 这个带状等离子体区域足够长以后, 由于其对电磁波的吸收和反射, 其将等离子体两侧的两束微波分割开. 随着时间的推移, 在等离子体附近的强场区, 不断出现新的等离子体带. 比较发现, 当其他条件相同时, 相干微波束产生的等离子体区域比非相干微波束大.关键词：相交高功率微波束大气击穿

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

Air breakdown by perpendicularly intersecting high-power microwave (HPM) is investigated by numerical solution of fluid-based plasma equations coupled with the Maxwell equations. For two coherently intersecting HPM beams, collisional cascade breakdown takes place only when the initial free electrons appear in or arrive at a region of 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 are 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 by coherent beams.
Keywords：intersecting high-power microwaveair breakdown