Non-equilibrium of charged particles in swarms and plasmas—from binary collisions to plasma effects
Non-equilibrium of charged particles in swarms and plasmas—from binary collisions to plasma effects
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群和等离子体中带电粒子的非平衡——从二元碰撞到等离子体效应
DOI：
10.1088/0741-3335/59/1/014026
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发表时间：
2016
影响因子：
2.2
通讯作者：
S. Dujko
中科院分区：
文献类型：
--
作者：
Z. Petrović;I. Simonović;S. Marjanović;D. Bošnjaković;D. Marić;G. Malović;S. Dujko
在这篇文章中，我们展示了三个完全不同的低温等离子体例子，在这些例子中，人们可以遵循基本的二元过程(发生在纳米尺度上)与宏观放电行为及其应用的联系。第一个例子是关于高阶输运系数(二阶扩散或偏度)的性质；如何利用它来改进等离子体的建模，以及如何利用它来辨别相关横截面的细节。对运输数据进行这种建模和使用的先决条件是流体动力学近似适用。在第二个例子中，我们通过进行动力学建模展示了阻性板室粒子探测器中雪崩的实际发展(尽管它也可以通过使用群数据来实现)。电流和沉积的电荷波形可以准确地预测出时间分辨率，这使得我们可以通过调整混合气体的组成和外场来优化探测器。在这里，动力学建模是必要的，以建立高精度和支持流体模型的物理细节，使我们能够跟踪到拖缆的过渡。最后，我们展示了一个充满气体的正电子陷阱的例子，在所有的实际目的中，这种气体都是一种类似于群体的弱电离气体，并可以用这种方式建模。然而，低压决定了需要应用完整的动力学模型，并使用能量分布函数来解释系统的动力学。这样，就有可能确认一个已经确立的现象学，但以一种允许精确的定量比较和描述的方式，从而为可能的优化打开大门。
In this article we show three quite different examples of low-temperature plasmas, where one can follow the connection of the elementary binary processes (occurring at the nanoscopic scale) to the macroscopic discharge behavior and to its application. The first example is on the nature of the higher-order transport coefficient (second-order diffusion or skewness); how it may be used to improve the modelling of plasmas and also on how it may be used to discern details of the relevant cross sections. A prerequisite for such modeling and use of transport data is that the hydrodynamic approximation is applicable. In the second example, we show the actual development of avalanches in a resistive plate chamber particle detector by conducting kinetic modelling (although it may also be achieved by using swarm data). The current and deposited charge waveforms may be predicted accurately showing temporal resolution, which allows us to optimize detectors by adjusting the gas mixture composition and external fields. Here kinetic modeling is necessary to establish high accuracy and the details of the physics that supports fluid models that allows us to follow the transition to streamers. Finally, we show an example of positron traps filled with gas that, for all practical purposes, are a weakly ionized gas akin to swarms, and may be modelled in that fashion. However, low pressures dictate the need to apply full kinetic modelling and use the energy distribution function to explain the kinetics of the system. In this way, it is possible to confirm a well established phenomenology, but in a manner that allows precise quantitative comparisons and description, and thus open doors to a possible optimization.