Collaborative Research: Understanding Turbulent Mixing in Laboratory Magnetospheres

该奖项是对提交给NSF/美国能源部基础等离子体科学与工程伙伴关系联合征集NSF 09-596的提案的回应。该奖项为本科生参与整个研究工作提供资金，该研究工作由美国能源部根据与哥伦比亚大学(TBD)的合同单独提供资金。等离子体占可见宇宙的99%以上，等离子体的湍流混合是一个基本过程，在自然和人工情况下都是重要的。电离气体的湍流混合称为等离子体，当等离子体嵌入到强磁场中时，尤其令人着迷。磁化等离子体的混合有特殊的几何关系，耦合来自小尺寸和大尺寸漩涡状结构的能量，称为“涡流”，并通过显著的湍流“挤压”产生自组织。两所大学的一项合作将运营两个独特的设施，称为实验室磁层，其中包含高温电离气体，使用的磁场类似于我们地球和其他行星周围的磁场。新的测量将与新的理论和模拟相结合，将回答尚未解决的问题，包括：等离子体涡旋是如何耦合不同大小的能量的？等离子体在湍流混合过程中是如何演化的？是什么机制导致了动荡的自组织？新的科学进展将包括：(1)各种等离子体条件下湍流交换混合的全球成像和控制，(2)通过理解湍流箍缩来研究静电自组织，以及(3)通过对实验室磁层中的湍流混合进行自洽的非线性模拟来验证我们的低频湍流模型。这项研究具有广泛的影响，因为磁化等离子体的湍流混合是普遍存在的和基本的。了解实验室磁层中的湍流混合将增进我们对以下方面的理解：(1)发生在电离层中的过程，这对卫星通信很重要；(2)行星磁层中心区域内的湍流，这对空间气象模型很重要；以及(3)低维流体系统的各向异性混合，这对工业过程很重要。此外，这项合作研究使用备受尊敬的研究型大学的最先进设施来激励学生和科学家在类似磁层的磁场配置中探索等离子体动力学，并鼓励下一代科学家能够理解和控制高温电离物质。

This award is made in response to a proposal submitted to and reviewed under the NSF/DOE Partnership in Basic Plasma Science and Engineering joint solicitation NSF 09-596. The award provides funds to support undergraduate participation in the overall research effort, which is being funded separately by the DOE under contract to Columbia University (TBD).Plasmas constitute over 99% of the visible universe and turbulent mixing of plasmas is a fundamental process that is important both in natural and artificial situations. Turbulent mixing of ionized gas, called plasma, is especially fascinating when the plasma is embedded inside a strong magnetic force field. Mixing of magnetized plasma has special geometric relationships, couples energy from small and large sized vortex-like structures know as "eddies," and creates self-organization through a remarkable turbulent "pinch." A collaboration between two universities will operate two unique facilities, called laboratory magnetospheres, that contain high-temperature ionized gas using a magnetic force field that resembles the field that surround our Earth and other planets. New measurements will be combined with new theories and simulations that will answer unresolved questions including: How do plasma eddies couple energy at different sizes? How do plasmas evolve during turbulent mixing? What mechanisms cause turbulent self-organization? New science will advance including: (1) global imaging and control of turbulent interchange mixing in a variety of plasma conditions, (2) study of electrostatic self-organization through the understanding of the turbulent pinch, and (3) validating our models for lowfrequency turbulence by carrying out self-consistent nonlinear simulations of turbulent mixing in laboratory magnetospheres.This research has broad impact because turbulent mixing of magnetized plasma is ubiquitous and fundamental. Understanding turbulent mixing in laboratory magnetospheres will improve our understanding of (1) processes occurring in the ionosphere, which is important to satellite communication, (2) turbulence inside the central regions of planetary magnetospheres, which is important to space weather models, and (3) the anisotropic mixing of low-dimensional fluid systems, which is important to industrial processes. Additionally, this collaborative research uses state-of-the-art facilities at highly-regarded research universities to motivate students and scientists to explore plasma dynamics in a magnetic configuration that resembles a magnetosphere and to encourage the next generation of scientists able to understand and control high-temperature, ionized matter.