Wave drag due to dust acoustic waves in collisional dusty plasmas
Wave drag due to dust acoustic waves in collisional dusty plasmas
复制标题
碰撞尘埃等离子体中尘埃声波引起的波阻力
DOI：
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发表时间：
2004
影响因子：
1.5
通讯作者：
D. Winske
中科院分区：
文献类型：
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作者：
D. Winske
尘埃等离子体中尘埃颗粒上的离子拖曳力对射频放电中平衡尘埃层和空隙区域的形成有显着贡献。除了由于颗粒附近电场中离子的直接收集和离子动量传递而产生的阻力之外，尘埃颗粒还可能由于相干波的影响而受到阻力，例如由于外部施加的电场引起的等离子离子相对于带电颗粒的漂移而导致尘埃声波的增长。在这里，我们使用数值模拟研究了碰撞尘埃等离子体中不稳定尘埃声波引起的波阻力。我们研究一维周期系统中的阻力与晶粒尺寸以及中性离子和中性尘埃碰撞的函数关系，在一维周期系统中更容易研究不稳定特性本身，并且在非周期配置中研究非周期配置，以评估与尘埃阻力和空洞形成相关的影响。对于所考虑的参数范围，我们发现在没有背景碰撞的情况下，通过将等离子体离子捕获在静电波中，不稳定性趋于饱和，这对尘埃颗粒影响不大。包括离子-中性碰撞往往会抑制离子捕获，这反过来会导致更大的波幅和灰尘的捕获，从而对灰尘颗粒产生显着的阻力。包含中性尘埃碰撞会导致依赖于颗粒尺寸的结果，并且仅持续捕获并因此拖拽较大的颗粒。对于本研究的参数，波曳力远大于通常考虑的离子曳力。
The ion drag force on dust grains in a dusty plasma contributes significantly to the formation of equilibrium dust layers and void regions in radio-frequency discharges. In addition to the drag due to the direct collection of ions and to momentum transfer of ions in the electric field near grains, dust grains can also be subject to a drag force due to the effect of coherent waves, such as dust acoustic waves that can grow because of the drift of plasma ions relative to charged grains induced by an externally imposed electric field. Here, we examine wave drag due to unstable dust acoustic waves in a collisional dusty plasma using numerical simulations. We study the drag as a function of grain size as well as neutral-ion and neutral-dust collisions in both one-dimensional periodic systems, in which it is easier to study the instability properties per se, and in aperiodic configurations in order to assess effects associated with dust drag and void formation. For the parameter range considered, we find that in the absence of background collisions, the instability tends to saturate by trapping the plasma ions in the electrostatic waves, which does not affect the dust grains very much. Including ion-neutral collisions tends to suppress ion trapping, which in turn leads to larger wave amplitudes and trapping of the dust, resulting in significant drag on the dust grains. Inclusion of neutral-dust collisions leads to a grain size-dependent result, with the persistence of trapping of, and thus drag on, larger grains only. For the parameters of this study, the wave drag force is much larger than the ion drag usually considered.