Dynamics of Strongly Coupled Complex Plasma Systems with Directed Ion Flow

具有定向离子流的强耦合复杂等离子体系统的动力学

基本信息

批准号：
1707215
负责人：
Lorin Matthews
金额：
$ 23万
依托单位：
Baylor University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-01 至 2020-12-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1707215&HistoricalAwards=false
关键词：
Dynamics Strongly Coupled Complex Plasma

项目摘要

This research project will investigate wakes, a phenomenon widely encountered in nature and spanning a range of length scales. Wakes are observed in the bow shock of a neutron star speeding through interstellar gas, in cloud patterns as air flows past ocean islands, and behind rocks in flowing streams. Cyclists take advantage of the wake created by their teammates, riding close behind each other to conserve energy. This research investigates the wakes formed by positively charged ions flowing past negatively charged dust particles in a complex plasma. The micron-sized dust particles in a complex (dusty) plasma have the ability to self-organize into a wide variety of structures. Much like drafting cyclists, dust particles trapped in the flowing plasma tend to line up downstream of each other. The energy savings due to dust alignment in the wakefield has an effect on the dynamics and the stability of dust structures. Complex plasmas are an excellent system for studying dynamic effects such as structure formation, as they allow direct observation at easily accessible space and time scales. An investigation of the modes of oscillation and structural transitions in a complex plasma can also provide insight into the dynamics of other finite systems which cannot be easily imaged.Many dusty plasma experiments utilize dust grains suspended in the sheath formed between the plasma and a bounding surface. The electric fields present in the sheath accelerate the plasma ions towards the bounding surface, leading to an ion wake downstream of the grains. The primary objective of this research is to investigate the effect of the plasma wakefield interaction on the self-organization, dynamics, and phase transitions in self-assembled dust structures within a complex plasma environment. This research merges computational and experimental techniques. A dynamic computational simulation is needed, as forces, charges, and wakes all change with particle location and the proximity of other particles. Numerical models will provide self-consistent calculations of dynamics, charging and anisotropic screening of dust particles in an ion flow. Charging and wakefield formation will be linked to the plasma environment, defining the response of the plasma to boundary conditions. At the same time, experimental techniques are needed that can produce specific particle structures in a controlled manner. Laboratory experiments will employ state-of-the-art techniques designed to control and confine the dust within dust clouds, strings, clusters, and crystals with defined characteristics. Experimentally, dust particles will also be used as in situ probes to measure the local plasma environment providing data for use in the numerical models.

该研究项目将研究唤醒，这是一种在自然界广泛遇到的现象，并跨越了一系列长度尺度。在中子星的弓令人震惊中，当空气流过海洋岛，在流动的溪流中，在云模式中速度有唤醒。骑自行车的人会利用队友创造的唤醒，彼此近在咫尺以节省能量。这项研究调查了复杂等离子体中充满负电荷的灰尘颗粒的正带带正电荷形成的唤醒。复合物（尘土飞扬）中的微米大小的灰尘颗粒具有自我组织成各种结构的能力。就像起草骑自行车的人一样，被困在流动的血浆中的灰尘粒子倾向于彼此在下游。韦克菲尔德（Wakefield）中的灰尘对齐产生的节能对灰尘结构的动力学和稳定性产生了影响。复杂的等离子体是研究动态效应（例如结构形成）的绝佳系统，因为它们允许在易于访问的空间和时间尺度上进行直接观察。对复杂等离子体中振荡和结构过渡模式的研究也可以提供对其他有限系统的动力学的见解。许多尘土高血浆实验利用悬浮在等离子体和边界表面之间形成的鞘内的灰尘晶粒。鞘中存在的电场将等离子体离子朝向边界表面加速，从而导致谷物下游的离子唤醒。这项研究的主要目的是研究等离子体韦克菲尔德相互作用对复杂等离子体环境中自组装灰尘结构中自组织，动力学和相变的影响。这项研究合并了计算和实验技术。需要动态计算模拟，因为力，电荷和唤醒都随着粒子位置和其他粒子的接近性而变化。数值模型将提供对离子流中灰尘颗粒的动力学，充电和各向异性筛选的自洽计算。充电和Wakefield的形成将与等离子体环境相关，从而定义了等离子体对边界条件的响应。同时，需要实验技术，可以以受控方式产生特定的粒子结构。实验室实验将采用旨在控制和局限尘埃的最新技术，这些技术具有定义特征的尘埃，弦，簇和晶体。在实验上，灰尘颗粒还将用作原位探针，以测量提供数据用于数值模型的局部血浆环境。