Charged Particulates in Low-temperature Plasmas

低温等离子体中的带电粒子

• 批准号: 9215882
• 负责人: John Goree
• 金额: $ 21.6万
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-06-01 至 1997-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9215882&HistoricalAwards=false
• 关键词: Charged; Particulates; Low; temperature; Plasmas

An experimental and theoretical study is proposed for low temperature plasmas that contain particulates. A plasma is an ionized gas, and in this work we will concentrate on weakly- ionized plasmas of the kind that are used widely in industry for manufacturing semiconductors, optical materials, and magnetic media. In a plasma, particulates (i.e. micron-size dust particles) become electrically charged. They also may grow in size by collecting sputtered atoms in the plasma. Particulates are a costly problem industrial uses of plasma processing because they can fall to a substrate and contaminate it. This is the motivation for this work. Experiments will be carried out to observe the time and density dependence of electrical charging of dust grains. These measurements will employ optical detection of grains in parallel-plate radio-frequency plasmas, and the results will be used to test theories of particulate charging in plasmas. Theoretical modeling will be performed to simulate the trapping of ions by charged grains. Negatively charged grains can trap positive ions in confined orbits, and this cause a reduction in the net electric forces that the charged grains experience. This modeling will employ numerical simulations of the motion of ions, including collisions with neutral atoms as well as the electric force created by charged grains.

提出了一个实验和理论研究的低 含有微粒的高温等离子体。 血浆是一种 电离气体，在这项工作中，我们将集中在弱- 在工业上广泛使用的电离等离子体， 制造半导体、光学材料和磁性材料 媒体 在等离子体中，微粒（即微米大小的灰尘 粒子）变得带电。 它们也可能生长在 通过收集等离子体中溅射的原子来调整尺寸。 微粒 等离子体处理的工业应用是一个昂贵的问题 因为它们可能会落到基底上并污染基底。 这 是这项工作的动机。 将进行实验 来观察电子的时间和密度依赖性， 粉尘颗粒的充电。 这些测量将采用 平行板射频中颗粒的光学检测 等离子体，其结果将用于测试理论， 等离子体中的颗粒充电。理论模型将 执行以模拟由带电颗粒捕获离子。 带负电荷的颗粒可以将正离子捕获在受限的空间中， 轨道，这导致净电力减少， 带电粒子的经验。 该模型将采用 离子运动的数值模拟，包括 与中性原子的碰撞以及电力 是由带电的颗粒形成的