三维磁重联动力学演化过程的数值模拟研究

Magnetic reconnection is an essential process in space, astrophysical, and laboratory plasmas, such as tearing modes in magnetically confined laboratory plasmas, coupling/interaction between solar wind/IMF (Interplanetary Magnetic Field) and magnetosphere plasmas, and flare, coronal heating, and coronal mass ejection in solar plasmas, fast energy transfer phenomena companied by particle acceleration and topological variation. Principally, magnetic reconnection must be a three dimensional (3D) process. However, studies for 3D reconnection have just been initiated in recent years, its physical picture is not very clear yet and its theory model is not fully explored either. This project proposes to investigate 3D magnetic reconnection penetratingly by 3D parallel particle-in-cell (PIC) code, for configuration characteristics and kinetic process of the magnetic reconnection, especially the motion characteristics of the ion and the electron in the diffusion region and the current system during reconnection. Furthermore, the 3D configuration of magnetopause magnetic reconnection will be also studied, and the results are applied to the SPERF (Space Plasma Environment Research Facility), a new terrella device as a part of State Major Infrastructure of Science and Technology, under construction at Harbin Institute of Technology for researching on magnetopause reconnection on the ground. The results will help us to deeply understand the 3D geometrical features and kinetic dynamics of magnetic reconnection, and to enrich the theoretical framework for the 3D model of the magnetic reconnection, and advance the researches on the reconnection in space and experimental plasma.

磁重联是空间、天体及实验室等离子体中普遍存在的物理现象，空间物理中行星际磁场与地球磁场的耦合、天体物理中耀斑和日冕加热、磁约束等离子体的各种撕裂模不稳定性等许多伴随拓扑位形变化及粒子加速的快速能量转化过程都与磁重联密切相关。磁重联本质上是三维的，然而三维磁重联的研究刚刚起步，物理图像尚不清晰、理论模型需要进一步探讨。本项目拟采用三维并行粒子模拟程序，对三维磁重联过程及其动力学演化特征进行深入研究，重点研究磁重联的三维结构特征、扩散区内粒子的运动特性及磁重联的电场和电流体系。并进一步对哈尔滨工业大学正在建设的国家重大科技基础设施“空间环境地面模拟”装置—空间等离子体环境模拟与研究系统将进行的磁重联实验开展模拟预研工作，希望通过本项目的研究加深对三维磁重联的结构特征和粒子动力学特性的理解，完善三维磁重联的相关理论，推动空间磁重联研究进程，为地面磁重联实验研究方案提供合理建议，降低科学研究风险。

磁重联是空间、天体及实验室等离子体中普遍存在的物理现象，空间物理中行星际磁场与地球磁场的耦合、天体物理中耀斑和日冕加热、磁约束等离子体的各种撕裂模不稳定性等许多伴随拓扑位形变化及粒子加速的快速能量转化过程都与磁重联密切相关。磁重联本质上是三维的，然而三维磁重联的研究刚刚起步，物理图像尚不清晰、理论模型需要进一步探讨。本项目采用三维模拟程序，对多种情况下的磁重联过程进行了研究，包括二维/三维非对称磁重联的结构和粒子的行为特征，离子尺度多电流片体系中的磁重联过程转变为哨声波调制的快速磁重联过程，多温度等离子体的磁重联率的变化规律和流场多尺度结构，总结SPERF装置磁重联过程的驱动依赖规律，分析了古月地共存体系中的磁重联过程。本项目的研究成果将加深对三维磁重联的结构特征的理解，为完善三维磁重联的相关理论提供支持，并为地面磁重联实验研究方案提供合理建议。