Fundamental Study of Aerosol Charging by Ions and Free Electrons in the Transition and Free-Molecule Regimes

9304152 PUI拟议的研究涉及过渡和自由分子区域中离子和自由电子对气溶胶荷电的实验和理论研究。它的目的是解决现有的理论和实验之间的差异。气溶胶充电和随后在电场中操纵颗粒物是测量、分类和收集颗粒物的有效手段。该项目将首先专注于开发一种低颗粒损失的气溶胶充电器，能够在真空和高纯度气体中运行。随后将进行离子和自由电子对气溶胶充电的实验研究。将测量气溶胶电荷分布。这种检验装药理论的方法比传统的装药分数测量更灵敏。得到玻耳兹曼碰撞方程的数值解，与现有的理论和获得的数据进行比较。这项研究的结果应有助于更好地了解基本的转移过程，并为提高空气污染控制行业中静电沉淀物的收集效率、材料行业中纳米颗粒的测量和分类以及微电子行业中等离子体反应器中的颗粒污染物控制提供必要的知识基础。***

9304152 Pui The proposed study deals with experimental and theoretical investigations of aerosol charging by ions and free electrons in the transition and free-molecule regimes. It is aimed to resolve existing discrepancies between theories and experiments. Aerosol charging and the subsequent manipulation of the particles in an electric field are effective means of measuring, classifying and collecting them. The project will first focus on developing an aerosol charger of low particle-loss, capable of operating under vacuum and in high purity gases. It will be followed by experimental studies of aerosol charging by ions and free electrons. Aerosol charge distributions will be measured. This method of testing charging theories is more sensitive than the traditional charged fraction measurement. A numerical solution to the Boltzmann collision equation will be obtained to compare with the existing theories and with data obtained. The results of this study should provide a better understanding of fundamental transfer processes and the needed knowledge base towards improving the collection efficiency of electrostatic precipitations in the air pollution control industry, measuring and classifying nanometer particles in the materials industry, and controlling particulate contaminants in plasma reactors in the microelectronics industry. ***