Multi-Dimensional Simulations of Double Layers, Ion Phase Space Holes, and Ion Acoustic Solutions Observed in the Magnetosphere and Ionosphere

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。局部双极电场脉冲已被许多卫星任务在地球等离子体环境中观测到，包括极光电离层、磁层区域（例如，磁尖、磁鞘和磁尾）和太阳风。本文提出的研究工作将涉及与极光上行电流区相关的等离子体条件下离子空穴、双层和离子声孤子的结构和演化。利用多维单元内粒子代码，PI将解决一些长期存在的问题，包括在多相空间维度的磁场中倾斜双层的稳定性，包括垂直加热如何影响双层的演变以及二维双层是否准稳定。最后，研究了离子空穴和离子声孤子的演化与双层演化的关系。本提案中提出的研究机会将提供给约翰布朗大学（JBU）的数学和科学本科生。这些机会将使学生参与世界一流的研究，参加国家会议，并与国家实验室、大型研究型大学和工业界的研究人员互动。此外，这项研究通过PIs的合作者在JBU（一所主要致力于本科教育的文科大学）和科罗拉多大学博尔德分校之间架起了一座桥梁。最后，作为这项研究的结果而开发的PIC代码将产生更广泛的影响，因为PI将使用这些代码来解决与基本电动力学相关的问题，并将这些结果纳入JBU的一些物理课程。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Localized bipolar electric field pulses have been observed by many satellite missions throughout Earth's plasma environment including the auroral ionosphere, regions of the magnetosphere (e.g., the cusp, the magnetosheath, and the magnetotail), and in the solar wind. The research effort proposed here will address the structure and evolution of ion holes,double layers, and ion acoustic solitons in plasma conditions relevant to the auroral upward current region. Using a multidimensional particle-in-cell code, The PI will address some long-standing questions regarding the stability of oblique double layers in a magnetic field in multiple phase space dimensions, including an investigation of how perpendicular ion heating affects the evolution of the double layer and whether a 2D double layer is quasi-stable. Finally, the evolution of ion holes and ion acoustic solitons will be studied in relation to the double layer evolution. The research opportunities presented in this proposal will be accessible to math and science undergraduate students at John Brown University (JBU). These opportunities will allow students to engage in world class research, attend national conferences and interact with researchers at national laboratories, larger research universities, and those in industry. Furthermore, this research provides a bridge between JBU, a liberal arts university devoted primarily to undergraduate education, and the University of Colorado, Boulder through the PIs collaborators. Finally, the PIC code that is developed as a results of this research will have a broader impact since the PI will use the code to solve problems related to basic electrodynamics and incorporate these results into some of the physics courses at JBU.