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

[9304152] Pui提出的研究涉及离子和自由电子在跃迁和自由分子状态下对气溶胶充电的实验和理论研究。它旨在解决理论与实验之间存在的差异。气溶胶带电和随后在电场中对粒子的操纵是测量、分类和收集它们的有效手段。该项目将首先专注于开发一种低颗粒损失的气溶胶增压器，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。这种测试电荷理论的方法比传统的电荷分数测量方法更灵敏。将得到玻尔兹曼碰撞方程的数值解，并与现有理论和得到的数据进行比较。本研究的结果将为提高空气污染控制行业静电沉淀的收集效率、材料行业纳米颗粒的测量和分类以及微电子行业等离子体反应器中颗粒污染物的控制提供更好的理解和所需的知识基础。＊＊＊

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. ***