Dispersive Alfven Waves in Space and Laboratory Plasmas

研究人员将研究磁化、强不均匀、低β实验室和空间等离子体中小尺度色散阿尔芬波的结构和动力学特征。 在磁层赤道面产生的色散阿尔芬波可将电磁能输送到电离层，并可造成顶部极光电离层和离散极光弧中的小规模强电场和电流。 该研究将使用一个模型的基础上减少两个流体磁流体动力学（MHD）的动力学方程，其中包括有限的电子和离子质量，温度和动力学效应的有限离子拉莫尔辐射的超低频电磁波在磁化等离子体的流体描述。 为了了解色散Alfven波的简化MHD描述的适用范围，研究人员将在大量控制良好的综合实验数据上验证物理模型及其数值实现。 特别是，这项工作涉及测试的理论模型的结果与实验室等离子体实验上进行的大型等离子体装置在加州大学洛杉矶分校。 研究结果将用于提高解释火箭和卫星在极光区测得的强场、电流和粒子通量的能力，并增进对实验室等离子体实验的了解。

The investigators will study structural and dynamical features of small-scale, dispersive Alfven waves in magnetized, strongly inhomogeneous, low-beta laboratory and space plasmas. Dispersive Alfven waves generated at the equatorial plane of the magnetosphere may transport electromagnetic power into the ionosphere and can be responsible for small-scale, intense electric fields and currents in the topside auroral ionosphere and in discrete auroral arcs. The study will used a model based on the reduced two-fluid magnetohydrodynamic (MHD) kinetic equations which incorporate effects of finite electron and ion masses, temperatures, and kinetic effects of the finite ion Larmor radious in the fluid description of ultra-low-frequency electromagnetic waves in a magnetized plasma. To understand the range of applicability of the reduced MHD description of dispersive Alfven waves, the investigators will verify the physical model and its numerical implementation on a large set of well-controlled, comprehensive experimental data. In particular, the effort involves testing the results of theoretical models with laboratory plasma experiments performed on the Large Plasma Device at UCLA. Results of the study will be applied to further the capability to interpret intense fields, currents and particle fluxes measured in the auroral zone on rockets and satellites as well as to advance understanding of laboratory plasma experiments.