两种带电尘埃颗粒的等离子体鞘层玻姆判据

采用流体方程和尘埃充电自洽模型研究了鞘边含有两种尘埃颗粒的等离子体玻姆判据. 通过拟牛顿法数值模拟了鞘边两种尘埃颗粒的存在对尘埃自身充电以及离子马赫数的影响. 两种尘埃颗粒中含量较少的尘埃颗粒数密度的增加, 导致两种尘埃颗粒表面悬浮势一个降低, 一个升高. 含量较少的尘埃颗粒的数密度越多和半径越小, 都会导致离子马赫数增大. 另外鞘边无论何种尘埃颗粒的速度增加, 鞘边离子马赫数都将减小.关键词：等离子体鞘层尘埃颗粒玻姆判据

The Bohm criterion for a plasma sheath with two species of charged dust particles

The fluid model and the self-consistent dust charging model are used to investigate the Bohm criterion for the plasma sheath including two species of charged dust particles. Numerical calculation results are obtained using quasi-Newton method. Effects of two species of dust particles on the dust charging and the ion Mach number are discussed. As the number density of the fewer dust particles is enhanced, different changes will take place on the surface potential of the two species of dust particles. Either more number density or smaller radius of the fewer dust particle may result in a larger ion Mach number. In addition, the ion Mach number will reduce when the velocity of any kind of dust particles at the sheath edge increases.
Keywords：plasma sheathdust particlesBohm criterion