Dynamical Processes in Strongly Coupled Complex Plasmas

复杂(尘埃)等离子体由浸泡在由电子、离子和中性原子组成的气体等离子体背景中的介观颗粒组成。这些颗粒变得高度带电，收集的电荷高达电子电荷的10000倍，并获得了高水平的势能。结果，它们变得强耦合，即它们的动力学由它们的势能决定，而不是它们的动能。在这种状态下，颗粒的行为在很大程度上模仿了原子和分子在凝聚态物质中经历的许多物理过程，尽管是在不同的尺度上。本课题通过理论分析和计算机模拟相结合的方法研究复杂等离子体的动力学行为。因此，它代表了一种新的方法来解决与凝聚态物理领域中的问题相关的问题，通过研究与固体、液体等中发生的过程相似的过程，在可以进行直接目测的情况下进行放大。这种方法要求研究人员对物理学的许多不同领域有广泛的了解。该项目的一个特殊的学术价值是使用了一种独特的分析方法，这种方法被称为准定域电荷近似，在早期的资金阶段已经得到了测试，它提供了对各种实验室实验和计算机模拟的解释。复杂(尘埃)等离子体在各种自然情况下都会发生。例如各种天体物理系统、地球环境、气体放电、半导体处理设施等。此外，实验室实验和轨道空间站无引力环境中的实验也产生了这些强耦合等离子体：从实验的角度来看，这些系统是独特的，因为它们结合了传统等离子体和(液体和固体)凝聚态物质的性质。这是一个关键特征，为研究各种高度不同的物理系统的性质提供了机会，例如胶体、恒星内部、磁体、低温“超冷”系统以及在宏观“可见”实验条件下在粒子加速器中产生的极热和致密的物质。该项目的主要计算机模拟程序将为学生提供广泛的计算方法培训和实践机会。参与的学生将被鼓励参观美国和海外的实验室和培训项目。

Complex (dusty) plasmas consist of mesoscopic grains immersed in the background of a gaseous plasma of electrons, ions and neutral atoms. The grains become highly charged, collecting electric charges up to 10000 times the electronic charge and acquiring a high level of potential energy. As a result, they become strongly coupled, i. e. their dynamics becomes governed by their potential, rather than their kinetic energy. In this state, the behavior of the grains largely mimics, albeit on a different scale, many of the physical processes that atoms and molecules undergo in condensed matter. This project addresses the dynamical behavior of complex plasmas through theoretical analysis combined with computer simulation. As such, it represents a novel approach to problems associated with issues in areas of condensed matter physics, by studying processes similar to those occurring in solids, liquids, etc. on a "magnified" scale where direct visual observation is possible. This approach requires that the investigators possess a broad overview of many different areas of physics. A special intellectual merit of the project is the use of a unique analytic method, created some time ago by the Principal Investigator and his colleagues, This method, referred to as the Quasi Localized Charge Approximation, was already tested in earlier funding periods where it provided interpretations of a variety of laboratory experiments and computer simulations.Complex (dusty) plasmas occur in a variety of natural situations. Examples are various astrophysical systems, the Earth's environment, gas discharges, semiconductor processing facilities, etc. In addition, laboratory experiments and experiments in gravitation free environment in the orbiting Space Station produce these strongly coupled plasmas as well: from the experimental point of view these systems are unique in that they combine properties of conventional plasmas and (liquid and solid) condensed matter. This is a key feature that provides the opportunity to study properties of various highly dissimilar physical system, such as colloids, stellar interiors, magnets, cryogenic "ultracold" systems and extremely hot and dense matter created in particle accelerators under macroscopic "visible" experimental conditions. The major computer simulation program of the project will open broad opportunities for students in training and practicing in computational methods. Participating students will be encouraged to visit US and overseas laboratories and training programs.