多成分电负性碰撞等离子体的鞘层玻姆判据

摘要

The Bohm criterion of the sheath in the multicomponent electronegative collisional plasma is developed with a two-fluid model. It is discussed that different charge particles affect the Bohm criterion for the sheath of a one-dimensional stationary plasma. Numerical calculation results are obtained through quasi-Newton method. It is shown that the upper and lower limits for the sheath criterion exist And the ion Mach number increases with the increase of secondary electron emission coefficient, it decreases with the increase of negative ions. In addition, the upper and lower limits for the sheath criterion depend on the temperature of ions, the ion-neutral collision and the charge of the ions.%采用双流体模型研究了多成分的电负性碰撞等离子体鞘层的玻姆判据,讨论了一维稳态情形下不同的带电粒子对鞘层玻姆判据的影响.采用拟牛顿法,得到了数值解.结果表明:玻姆判据存在上限和下限.二次电子发射系数越大,离子的马赫数越大；负离子的含量越多,离子的马赫数越小.鞘层中离子的温度、离子与中性粒子的碰撞以及离子的带电量对玻姆判据的上下限的取值都有一定的影响.