Kinetic Characterization of Three-Dimensional (3D) Magnetic Reconnection: A Transformative Step

该项目将研究磁重联过程中磁能转化为等离子体动能的微尺度区域内的等离子体和磁场条件。磁重联实际上是磁力线的断裂和重新连接，伴随着能量的爆炸性释放。这种爆炸性的能量释放是地球附近空间天气扰动的重要组成部分。卫星观测和等离子体模拟将结合起来研究能量转换过程。该提案的科学目标与美国国家科学基金会-能源部等离子体物理伙伴关系的优先事项密切相关。作为该计划的一部分，NSF和能源部(DOE)将合作支持调查。该项目将为博士后提供研究培训，为未来的科学劳动力做出贡献。这项关于等离子体中一个关键的能量转换过程(磁重联)的研究结果将引起地球空间以外的科学学科的兴趣，包括天体物理学和聚变实验室。从长远来看，关于空间风暴期间爆炸能量释放触发因素的新知识将改善空间天气预测。拟议调查的一个重要元素是卫星对空间环境的观测和尖端等离子体模拟的综合。空间数据将从最近发射的4颗组成磁层多尺度(MMS)任务的卫星配置中获得。MMS能够以比以往任何太空任务高两个数量级的速度测量电子的状态。这是至关重要的，以便在卫星飞行时解析这些空间非常有限的区域的等离子体结构。模拟将使用最先进的3D粒子单元(PIC)模型进行，该模型经过优化，可以在超级计算机上高效运行。预计将在以下方面取得重大进展：(1)在各种自然发生的三维磁场和电场配置中的等离子体能化；(2)在磁层顶和磁尾的重联区中的电场和磁场结构及其自洽等离子体流型。

This project will investigate the plasma and magnetic field conditions in the micro-scale regions where magnetic energy is converted to plasma kinetic energy during magnetic reconnection. Magnetic reconnection is, in effect, the breaking and reconnecting of magnetic field lines, which is accompanied by an explosive release of energy. This explosive energy release is an important component of space weather disturbances in Earth's vicinity. Satellite observations and plasma simulations will be combined to study the energy conversion process. The science objectives of this proposal are closely aligned with the priorities of the NSF-DOE Plasma Physics Partnership. As part of this program, NSF and the Department of Energy (DOE) will collaborate in supporting the investigation. The project will provide research training for a postdoctoral student, contributing to the future scientific workforce. The results of this research into a key energy conversion process in plasmas (magnetic reconnection) will be of interest to scientific disciplines outside of Geospace, including the astrophysics and laboratory fusion communities. In the longer term, new knowledge about the triggers of explosive energy release during space storms will improve space weather prediction.An important element of the proposed investigation is the synthesis of satellite observations of the space environment and cutting-edge plasma simulations. The space data will be obtained from a recently launched configuration of 4 satellites that form the Magnetospheric Multiscale (MMS) mission. MMS is capable of measuring the state of the electrons at two orders of magnitude higher cadence than any previous space missions. This is vital in order to resolve plasma structures in these very spatially limited regions as the satellites fly through. The simulations will be done using a state-of-the-art 3D Particle-in-Cell (PIC) model optimized to run efficiently on supercomputers. Significant advances in knowledge are expected about: (1) plasma energization in various types of naturally occurring 3D magnetic and electric field configurations and (2) electric and magnetic field structures and their self-consistent plasma flow patterns in reconnection regions at the magnetopause and in the magnetotail.