Collisionless Magnetic Reconnection

磁重联是大范围环境中自然界重要现象的基础，包括太阳耀斑、磁层亚暴和实验室聚变实验的中断。在磁重联过程中发生的磁场的拓扑变化需要打破理想的MHD冻结磁通约束。目前的证据是，只有在完整的3-D系统的背景下，才能理解无碰撞的磁重联。鉴于对控制无碰撞磁重联的基本物理问题的了解，以及可用的数值工具，最终解决重要的磁重联问题的时机已经成熟。该提案将勾勒出一个雄心勃勃的分析和计算计划，以了解3-D系统中的无碰撞磁重联。我们将探讨电子与离子动力学在控制重联速率中的作用，湍流在打破电子和离子电流层中的作用，以及从磁场到电子和离子的能量流的分支比。将与正在进行的和过去的实验室重新连接实验以及磁层中的卫星观测进行比较。

Magnetic reconnection underlies important phenomena in nature in a broad range environment, including solar flares, magnetospheric substorms and disruptions in laboratory fusion experiments. The topological change in the magnetic field which occurs during magnetic reconnection requires a breaking of the ideal MHD frozen flux constraint. The present evidence is that collisionless magnetic reconnection can only be understood in the context of a full 3-D system. Given the understanding of the basic physics issues controlling collisionless magnetic reconnection and the numerical tools which are available, the time is ripe to finally solve important magnetic reconnection problems. The proposal will outline an ambitious analytical and computational program to understand collisionless magnetic reconnection in a 3-D system. The role of electron versus ion dynamics in controlling the rate of reconnection, the role of turbulence in breaking up the electron and ion current layers and finally the branching ratio of energy flow from the magnetic field into electrons and ions will be explored. Comparisons will be made to ongoing and past laboratory reconnection experiments as well as satellite observations in the magnetosphere.