Dynamical Processes in Strongly Coupled Complex Plasmas

复杂（尘埃）等离子体由介观颗粒组成，这些颗粒浸没在由电子、离子和中性原子组成的气体等离子体的背景中。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而不是动能控制。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，尽管尺度不同。本项目通过理论分析与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，它代表了一种与凝聚态物理领域相关问题的新方法，通过在“放大”的尺度上研究类似于固体、液体等发生的过程，在那里直接的视觉观察是可能的。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智力价值是使用了一种独特的分析方法，这种方法是由首席研究员和他的同事们在一段时间前创造的，这种方法被称为准局部电荷近似，已经在早期的资助阶段进行了测试，它提供了各种实验室实验和计算机模拟的解释。复杂（尘埃）等离子体出现在各种自然情况下。例如各种天体物理系统、地球环境、气体排放、半导体处理设施等。此外，实验室实验和在轨道空间站的无重力环境中进行的实验也产生了这些强耦合等离子体：从实验的角度来看，这些系统的独特之处在于它们结合了传统等离子体和（液体和固体）凝聚态物质的特性。这是一个关键特征，提供了研究各种高度不同的物理系统的性质的机会，如胶体、恒星内部、磁铁、低温“超冷”系统和在宏观“可见”实验条件下在粒子加速器中产生的极热和致密物质。该项目的主要计算机模拟程序将为学生提供广泛的训练和实践计算方法的机会。参加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.