Numerical Simulations of Magnetic Reconnection in an Asymmetric Current Sheet
WANG Pei-Ran1, HUANG Can1, LU Quan-Ming1**, WANG Rong-Sheng2, WANG Shui1
1CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Science, University of Science and Technology of China, Hefei 230026 2Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029
Abstract：Previous particle-in-cell simulations have shown that electron phase-space holes (electron holes), where the associated parallel electric field has a bipolar structure, exist near the four separatrices in anti-parallel magnetic reconnection. By performing two-dimensional (2-D) particle-in-cell (PIC) simulations, here we investigate magnetic reconnection in an asymmetric current sheet, with emphasis on the parallel electric field near the separatrices. Compared with magnetic reconnection in a symmetric current sheet, it is found that the parallel electric field with a bipolar structure only exists around the separatrices in the upper region with a lower density (upper separatrices). Such a bipolar structure of the parallel electric field is considered to be associated with electron holes resulting from the nonlinear evolution of the electron beam instability excited by the high-speed electron flow formed after their acceleration around the X line. The disappearance of the parallel electric field around the separatrices in the lower region with a higher density (lower separatrices) may be due to the transverse instability, which is unstable in a weak magnetized plasma.
. [J]. 中国物理快报, 2013, 30(12): 125202-125202.
WANG Pei-Ran, HUANG Can, LU Quan-Ming, WANG Rong-Sheng, WANG Shui. Numerical Simulations of Magnetic Reconnection in an Asymmetric Current Sheet. Chin. Phys. Lett., 2013, 30(12): 125202-125202.
2013, Vol. 30 
