Discrete stochastic charging of aggregate grains
Discrete stochastic charging of aggregate grains
复制标题
骨料颗粒的离散随机充电
DOI：
10.1103/physreve.97.053207
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发表时间：
2018
影响因子：
2.4
通讯作者：
Hyde, Truell W.
中科院分区：
文献类型：
--
作者：
Matthews, Lorin S.;Shotorban, Babak;Hyde, Truell W.
沉浸在等离子体环境中的尘埃粒子通过随机收集电子和离子而带电，导致尘埃电荷在平衡值上下波动。小颗粒（半径小于1 μm）或细小等离子体环境中的颗粒对单个电子或离子的加入非常敏感。在这里，我们提出了一个数值模型，该模型允许检查聚集颗粒表面的离散随机电荷波动，并确定这些波动对颗粒聚集动力学的影响。我们表明，在具有等效半径的球体上，聚集体颗粒上电荷的平均值和标准差遵循与预测相同的趋势，尽管聚集体表现出与预测值较大的变化。在某些等离子体环境中，这些电荷波动发生在与聚合体生长动力学相关的时间尺度上。耦合动力学和电荷模型表明，电荷波动倾向于产生比在电荷静止环境中形成的聚集体更线性或丝状的聚集体。
Dust particles immersed in a plasma environment become charged through the collection of electrons and ions at random times, causing the dust charge to fluctuate about an equilibrium value. Small grains (with radii less than 1 μm) or grains in a tenuous plasma environment are sensitive to single additions of electrons or ions. Here we present a numerical model that allows examination of discrete stochastic charge fluctuations on the surface of aggregate grains and determines the effect of these fluctuations on the dynamics of grain aggregation. We show that the mean and standard deviation of charge on aggregate grains follow the same trends as those predicted for spheres having an equivalent radius, though aggregates exhibit larger variations from the predicted values. In some plasma environments, these charge fluctuations occur on timescales which are relevant for dynamics of aggregate growth. Coupled dynamics and charging models show that charge fluctuations tend to produce aggregates which are much more linear or filamentary than aggregates formed in an environment where the charge is stationary.