The influence of boundary conditions on the distribution of energetic electrons during collisionless magnetic reconnection  

作　　者：王磊 黄灿 陈冬可 杨忠炜 杜爱民 葛亚松 Lei WANG;Can HUANG;Dongke CHEN;Zhongwei YANG;Aimin DU;Yasong GE(CAS Engineering Laboratory for Deep Resources Equipment and Technology,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,People’s Republic of China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100029,People’s Republic of China;State Key Laboratory of Space Weather,National Space Science Center,Chinese Academy of Sciences,Beijing 100190,People’s Republic of China)

机构地区：[1]CAS Engineering Laboratory for Deep Resources Equipment and Technology,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,People’s Republic of China [2]College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100029,People’s Republic of China [3]State Key Laboratory of Space Weather,National Space Science Center,Chinese Academy of Sciences,Beijing 100190,People’s Republic of China

出　　处：《Plasma Science and Technology》2024年第4期79-84,共6页等离子体科学和技术（英文版）

基　　金：the support from the Key Research Program of the Chinese Academy of Sciences(No.ZDBSSSW-TLC00105);the National Key R&D Program of China(No.2022YFF0503200);National Natural Science Foundation of China(Nos.41974173 and 42274224);the Youth Innovation Promotion Association,Chinese Academy of Sciences(No.2019066)。

摘　　要：We conducted 2-D particle-in-cell simulations to investigate the impact of boundary conditions on the evolution of magnetic reconnection. The results demonstrate that the boundary conditions are crucial to this evolution. Specifically, in the cases of traditional periodic boundary(PB) and fully-opened boundary(OB) conditions, the evolutions are quite similar before the system achieves the fastest reconnection rate. However, differences emerge between the two cases afterward. In the PB case, the reconnection electric field experiences a rapid decline and even becomes negative, indicating a reversal of the reconnection process. In contrast, the system maintains a fast reconnection stage in the OB case. Suprathermal electrons are generated near the separatrix and in the exhaust region of both simulation cases. In the electron density depletion layer and the dipolarization front region, a larger proportion of suprathermal electrons are produced in the OB case. Medium-energy electrons are mainly located in the vicinity of the X-line and downstream of the reconnection site in both cases. However, in the OB case, they can also be generated in the electron holes along the separatrix. Before the reverse reconnection stage, no high-energy electrons are present in the PB case. In contrast, about 20% of the electrons in the thin and elongated electron current layer are high-energy in the OB case.

关 键 词：magnetic reconnection electron energization particle-in-cell simulation 

分 类 号：O53[理学—等离子体物理] O469[理学—物理]