Investigation of the sheath formation in a dusty plasma containing energetic electrons and nano-size dust grains
Investigation of the sheath formation in a dusty plasma containing energetic electrons and nano-size dust grains
复制标题
DOI：
10.1063/1.4764074
复制
发表时间：
2012-10
影响因子：
2.2
通讯作者：
G. Foroutan;A. Akhoundi
中科院分区：
文献类型：
--
作者：
G. Foroutan;A. Akhoundi
用定常多流体方程的数值模拟方法研究了高能电子束作用下尘埃等离子体鞘的结构。研究发现，即使是极少量的高能电子也能强烈地改变鞘层参数，尤其是鞘层厚度。根据束流的大小，可以识别出两种不同的鞘层厚度区域；在小束流密度下，鞘层处于薄鞘区域，其厚度随束流密度呈线性增长。随着束流密度的增加，在一定的束流能量或束流数密度下，鞘层向宽度增大近3倍的厚鞘区域急剧转变。对应于这两个区域之间的跃迁的束流参数取决于背景等离子体的参数。束流跃迁能随电子温度和尘埃数密度的增加而增大，随尘埃半径的增大而减小。另一方面，束流跃迁是一种新的研究方法。
Numerical simulations of the stationary multi-fluid equations are used to study the structure of a dusty plasma sheath in the presence of a beam of energetic electrons. It is found that even a small number of energetic electrons can strongly modify the sheath parameters, specially the sheath thickness. Depending on the magnitude of the beam flux, two different regimes of sheath thickness can be recognized; At small beam fluxes, the sheath is in the regime of thin sheath and its thickness grows linearly with the beam flux. As the beam flux increases, at a certain beam energy or beam number density, the sheath demonstrates a sharp transition to the regime of thick sheath where the width is almost three times larger. The beam parameters corresponding to the transition between the two regimes depend on the parameters of the background plasma. The beam transition energy increases with the electron temperature and dust number density while decreases with the dust radius. On the other hand, the beam transition n...