Physics of Plasma Confined by a Dipole Magnetic Field

建议的工作是使用新组装的无碰撞Terrella实验（CTX）进行和分析两个特定的实验。这些实验的结果将大大扩展我们对行星磁层中无碰撞粒子输运的理解。它们将用于测试由偶极磁场的动态和静态非轴对称扰动引起的混沌和输运的基本理论。在第一个实验中，通过操作我们的微波等离子体源产生被困在偶极子磁场中的高能电子，直接加热偶极子的高场区域。正如在其他地方看到的，这些电子将变得不稳定到低频交换不稳定的频谱，并诱导无碰撞径向输运。我们将测量波动的幅度、频率和波长，混沌开始的条件，以及由此产生的输运的大小。我们也将能够观察到边缘稳定的压力分布和测试绝热输运理论。在第二个实验中，我们将对高能电子等离子体施加多极静态扰动，打破方位角对称并破坏角动量守恒。通过测量随着扰动强度的增加而被困电子约束的减少，我们将能够记录导致三维混沌的条件。这些实验将以数值和理论分析为指导和解释。通过在实验室和数值模拟之间建立相关性，我们将展示磁波动如何诱导偶极子场中高能粒子的输运和加热，并为行星磁层中发生的类似过程建立模型。

The proposed work is to conduct and analyze two specific experiments using the newly assembled Collisionless Terrella Experiment (CTX). The results from these experiments will significantly expand our understanding of collisionless particle transport in planetary magnetospheres. They will be used to test basic theories of chaos and transport induced by dynamic and static non-axisymmetric perturbations to a dipole magnetic field. For the first experiment, energetic electrons trapped within the dipole magnetic field will be generated by operating our microwave plasma source so as to directly heat the high-field regions of the dipole. As seen elsewhere, these electrons will become unstable to a spectrum of low-frequency interchange instabilities and induce collisionless radial transport. We will measure the amplitude, frequency, and wavelength of the fluctuations, the condition for the onset of chaos, and the magnitude of the resulting transport. We will also be able to observe marginally-stable pressure profiles and test theories of adiabatic transport. For the second experiment, we will impose a multipolar static perturbation to the energetic electron plasma breaking azimuthal symmetry and destroying conservation of angular momentum. By measuring the decrease in the confinement of the trapped electrons as the magnitude of the perturbation is increased, we will be able to document the conditions leading to three-dimensional chaos. These experiments will be guided and interpreted by numerical and theoretical analysis. By making correlations between laboratory and numerical simulations, we will demonstrate how magnetic fluctuations can induce transport and heating of energetic particles in dipole fields and establish models for similar processes occurring in planetary magnetospheres.