Particles in Plasmas: Electron Transport Coefficients and Discharge Stability

中低压等离子体和气体放电用于各种技术上重要的应用（例如，等离子体加工，气体激光器，等离子体开关）。这些等离子体的气体环境不可避免地受到来自电极、壁和气相化学反应的灰尘和颗粒物质的污染。在本研究计划中，将建立第一性原理计算机模型来描述粒子物质对等离子体特性的扰动和等离子体不稳定性的引发。开发该模型的目标是预测中低压辉光放电（1atm）中粒子的存在导致的电子传递系数的变化以及电弧和流线的形成；并根据颗粒的大小、类型和分布，对此类排放的容忍度设定操作限制。这项研究的结果将为长寿命气体放电装置的设计者提供一种新的能力，用这种能力来预测和纠正设备在非原始环境中的性能，这些设备必须在这些环境中运行。这里开发的计算技术也将直接适用于预测从电极上的不均匀性开始的流线形成。

Moderate and low pressure plasmas and electrical gas discharges are used in a variety of technologically important applications (e.g., plasma processing, gas lasers, plasma switches). The gaseous environments of these plasmas are unavoidably contaminated with dust and particulate matter originating from electrodes, walls, and gas phase chemical reactions. In this research program, a first principles computer model will be developed to describe the perturbation of plasma properties and the initiation of plasma instabilities by particulate matter. The goals of developing the model are to predict the change in electron transport coefficients and the formation of arcs and streamers resulting from the presence of particulates in moderate to low pressure glow discharges ( 1 atm); and to set operational limits on the tolerance of such discharges to the size, type, and distribution of particles. The results of this study will provide a new capability to the designers of long lived gas discharge devices with which to predict and correct the performance of their devices in the non-pristine environments in which they must operate. The computational techniques developed here will also be directly applicable to predicting the onset of streamer formation from non-uniformities on electrodes.