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用Hall MHD数值模拟的方法研究了Hall等离子体中不同初始粒子载流情形下磁场拓扑形态结构的改变以及场向电流与Alfvén波的产生.在考虑了初始离子载流子的影响后,模拟结果中磁场的拓扑形态结构更加复杂.模拟结果中除了传统的By四极结构以外,还出现了一个与传统By四极结构相反的反四极结构,这种结构的出现使Hall MHD理论能解释完全电子载流情形下不能解释的观测现象,作为事例给出了Cluster卫星观测事例.同时还得出以下几个非常有意义的结果:1)受Hall效应影响的区域(空间变化尺度小于或相当离子回旋半径的区域)电子与离子分离.在非Hall效应影响的大部分区域,受初始离子+y方向运动的影响整个磁结构向+y方向偏移;而在受Hall影响的较小区域,受电子运动影响磁力线向+y方向弯曲.随之,By产生;2)由于By的出现,场向电流(FACs)产生.与完全电子载流的情形相比,结果中场向电流分布的中心随离子载流比例的增加向+y方向偏移,场向电流主要分布在y>0的区域;3)模拟结果中Ae≈0.76,Ai≈1.36,Ae×Ai≈1.03,完全符合Hall等离子体中的瓦伦关系,证实了Alfvén波的存在.
The Hall MHD numerical simulation method was used to study the change of the magnetic field topological structure and the field current and Alfvén wave generation under the different initial particle current in the Hall plasma. After considering the initial ion carrier influence, the simulation results The topological structure of the magnetic field is more complicated. In addition to the traditional By-quadrupole structure, an anti-quadrupole structure opposite to the traditional By-quadrupole structure appears in the simulation results. The appearance of this structure enables Hall MHD theory to be completely explained Observations of Cluster satellite observations are given as examples in the case of electron-current-current observations that can not be interpreted, with the following very interesting results: 1) Regions affected by the effects of the Hall effect (where the spatial variation is less than or equal to that of ions The region of gyration radius) Electrons and ions are separated. In most of the regions that are not affected by the Hall effect, the whole magnetic structure is shifted in the + y direction by the movement of the initial ions + y direction. In the smaller region affected by the Hall, Electron motion affects the magnetic field lines to bend in the + y direction, which in turn generates By; 2) Field currents (FACs) are generated due to the appearance of By. As a result, compared with the case of complete electron current flow The center of the field current distribution is shifted to the + y direction with the increase of the ion current carrying ratio, and the field current is mainly distributed in the area where y> 0; 3) In the simulation results, Ae≈0.76, Ai≈1.36, Ae × Ai≈1.03 , In full compliance with the Wallenian relationship in the Hall plasma, confirms the presence of Alfvén waves.