Studies of turbulence, transport and flows in the Large Plasma Device

这个项目的目标是了解实验室等离子体中流动、湍流和输运之间的相互作用。实验将使用大型等离子体设备(LAPD)进行，该设备是加州大学洛杉矶分校基础等离子体科学设施的一部分。这项工作将建立在最近观察到的由偏压驱动的旋转引发的Lapd粒子约束转变的基础上。在拟议的工作中，重点将重点放在平行边界条件在Lapd内的湍流、输送和流动中的作用。将构建一组限制器，以便在洛杉矶警察局的边缘建立定义明确但可变的平行边界条件。我们将研究平行边界条件下的湍流、输运以及驱动和自发流动的修正。第二个重点将是角动量输运和Lapd中的流动产生，重点是研究间歇对流在这些过程中的作用。此外，还讨论了一系列交替研究的主题，包括研究转变阈值随等离子体参数的变化，以及驱动流和约束转变的轴向相关性。这项拟议研究的学术价值来自于湍流、输运和流动在大范围等离子体中的基本重要性。对传输、湍流和流动之间相互作用的拟议详细研究将对等离子体物理学的广泛子领域产生影响，包括磁约束聚变以及空间和天体物理等离子体物理。拟议工作的更广泛影响将在研究和教育活动中实现。该提案的一个主要重点是培养一名攻读博士学位的研究生和一名本科生。这项拟议的工作将补充与LLNL合作的现有工作，将洛杉矶警察局的测量结果与3D布拉金斯基流体代码回合的预测进行比较。洛杉矶警察局可能进行的详细测量为Bout等模拟代码的预测能力提供了重要的测试。建立磁化等离子体中湍流和输运的预测能力对于在各种环境下促进对基本等离子体过程的理解是重要的，但对于磁聚变能量研究的进展尤其关键。本文提出的工作将在一定程度上有助于将LAPD建立为一个实验平台，用于测试当前(例如，Bout)和计划(例如，边缘运动模拟)大规模并行湍流模拟程序的能力。该建议已提交给NSF-DOE在等离子体科学和工程方面的伙伴关系08-589。该奖项由物理系等离子体物理项目资助。

The goal of this project is to gain understanding of the interaction between flows, turbulence, and transport in a laboratory plasma. Experiments will be performed using the Large Plasma Device (LAPD), which is part of the Basic Plasma Science Facility at UCLA. The work would build on the recent observation of a particle confinement transition triggered by bias-driven rotation in LAPD. In the proposed work, focus will be given to the role of parallel boundary conditions in turbulence, transport and flows in LAPD. A set of limiters will be constructed in order to establish well-defined, yet changeable, parallel boundary conditions in the edge of LAPD. Modifications in turbulence, transport, and driven and spontaneous flows with parallel boundary conditions will be investigated. A second focus will be on angular momentum transport and flow generation in LAPD, emphasizing a study of the role of intermittent convection in these processes. In addition, a set of topics for alternate lines of research are discussed, including studies of the scaling of the transition threshold with plasma parameters, and the axial dependence of driven flows and the confinement transition. The intellectual merit of the proposed research stems from the fundamental importance of turbulence, transport, and flows in a wide range of plasmas. The proposed detailed study of the interplay between transport, turbulence and flows will have an impact on a wide range of subfields of plasma physics, including magnetic confinement fusion, and space and astrophysical plasma physics.The broader impacts of the proposed work would be realized in both the research and educational activites. A major focus of the proposal is the training of one graduate student, working toward a PhD, and one undergraduate student. The proposed work will complement an existing effort in collaboration with LLNL to compare measurements in LAPD to predictions of the 3D Braginskii fluid code BOUT. The detailed measurements possible in LAPD provide a significant test of the predictive capabilities of a simulation code such as BOUT. Establishing a predictive capability in turbulence and transport in magnetized plasmas is important in advancing understanding of fundamental plasma processes in a variety of settings, but is especially critical to progress in magnetic fusion energy research. The work proposed here will, in part, help establish LAPD as an experimental platform for testing the capabilities of current (e.g., BOUT) and planned (e.g., edge kinetic simulation) massively-parallel turbulence simulation codes.This proposal was submitted to the NSF-DoE Partnership in Plasma Science and Engineering joint solicitation 08-589. This award is being funded by the Plasma Physics Program in the Division of Physics.