RUI: Equilibrium, Stability, Dynamics, and Transport Physics for Electron Plasma in a Toroidal Magnetic Field

RUI：环形磁场中电子等离子体的平衡、稳定性、动力学和输运物理

• 批准号: 0812893
• 负责人: Matthew Stoneking
• 金额: $ 16.88万
• 依托单位: LAWRENCE UNIVERSITY OF WISCONSIN
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-15 至 2012-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0812893&HistoricalAwards=false
• 关键词: RUI; Equilibrium; Stability; Dynamics; Transport

Prior NSF support was used to design and construct a new high performance toroidal trap for non-neutral plasmas (i.e. plasmas with a single sign of charged particle). In the past year, construction of the experiment was completed and early experiments conducted in a portion of the torus produced nearly steady state plasma conditions (several second confinement times). The present award permits the P.I. and his undergraduate students to explore the physics of long-lived toroidal non-neutral plasmas in much greater detail. The non-uniform character of the toroidal magnetic field in this experiment is predicted to ultimately limit the confinement to times on the order of ten seconds. Experiments will be conducted to identify the loss mechanism predicted by this as yet untested theory. Additional experiments will be conducted to identify the effect of the curved and non-uniform toroidal magnetic field on the natural modes of oscillation (i.e. waves) that propagate in non-neutral plasmas. In addition, the present award will fund development of instruments and techniques necessary to transition from (and diagnose) experiments in a portion of the torus, to confinement in the full torus. Experiments in which non-neutral plasmas are isolated for long times so that they can be observed and manipulated provide excellent "wind tunnels" for close testing of plasma and neutral fluid theories; helping refine our fundamental understanding of naturally occurring fluid systems and plasmas and of laboratory plasmas that find application in society. Non-neutral plasmas can be generated reproducibly and confined for very long times in traps with a simple geometry (i.e. a cylinder). However, until construction of the present device was completed, attempts to trap non-neutral plasmas in more complicated magnetic field arrangements (such as a torus) have resulted in very short trapping times (of order 100 microseconds). No other existing experiment is poised answer fundamental questions about the criteria for stable equilibrium states, the toroidal effects on plasma dynamics, and the limitations on confinement for such systems. The activity funded under this award will provide research experiences (as well as scientific authorship and presentation opportunities) for undergraduate students, inspiring some of them to pursue graduate work in physics. The apparatus will also be used to recruit promising high school students to the Lawrence University physics program and expose the campus and local communities to the subject of plasma physics.

先前的NSF支持被用于设计和构建一个新的高性能环形阱，用于非中性等离子体（即具有单符号带电粒子的等离子体）。在过去的一年里，实验的建设已经完成，在环面的一部分进行的早期实验产生了接近稳态的等离子体条件（几秒的约束时间）。目前的奖项允许P.I.和他的本科生更详细地探索长寿命环形非中性等离子体的物理学。在本实验中，环形磁场的非均匀特性预计最终将限制在10秒数量级的约束时间内。将进行实验，以确定这一尚未验证的理论所预测的损失机制。将进行额外的实验，以确定弯曲和非均匀的环形磁场对非中性等离子体中传播的振荡（即波）的自然模式的影响。此外，本奖项将资助从环面部分实验（和诊断）过渡到全环面限制所需的仪器和技术的开发。将非中性等离子体长时间隔离以便观察和操纵的实验为等离子体和中性流体理论的近距离测试提供了极好的“风洞”；帮助完善我们对自然发生的流体系统和等离子体以及在社会中应用的实验室等离子体的基本理解。非中性等离子体可以在具有简单几何形状（即圆柱体）的陷阱中可重复地产生并被限制很长时间。然而，在目前装置的构建完成之前，在更复杂的磁场安排（如环面）中捕获非中性等离子体的尝试导致了非常短的捕获时间（约100微秒）。没有其他现有的实验能够回答关于稳定平衡状态的标准、等离子体动力学的环面效应以及这种系统的约束限制等基本问题。该奖项资助的活动将为本科生提供研究经验（以及科学作者和演讲机会），激励他们中的一些人继续从事物理学的研究生工作。该装置还将用于招募有前途的高中生参加劳伦斯大学物理项目，并向校园和当地社区宣传等离子体物理学。