7th Asia-Pacific Conference on Plasma Physics, 12-17 Nov, 2023 at Port Messe Nagoya

Hall field structure analysis of three-dimensional magnetic reconnection inSPERF-AREX for simulated magnetopause events

X. He1, A. Mao1, 2, 3, M. Sun1, J. Zou1, X. Wang1, 2, 3
1School of Physics, Harbin Institute of Technology
2
Laboratory for Space Environment and Physical Sciences, Harbin Institute of Technology
3
China-Russia Belt and Road Joint Laboratory on Advanced Energy and Power Technology, Harbin
Institute of Technology
e-mail (speaker): h1750181686@gmail.com

Magnetic reconnection is a fast topologicalrearrangement of the magnetic field by either/both freeenergy due to the inhomogeneous distribution of plasma
currents or/and the external driving by injected energy,
resulting in rapid conversion of the magnetic energy into
the kinetic/thermal energy of the plasma. Of key
importance to the reconnection process in space is the Hall
physics and its accompanying Hall magnetic fields, as itallows reconnection to proceed at a rapid rate andindicates that the diffusion region is in proximity for insitu satellite observations.
The Hall field structures in two-dimensional (2D)
magnetic reconnection has been extensively investigated.
Within the diffusion region electrons and ions decouple
from the magnetic field on different spatial scales,
resulting in a characteristic Hall quadrupolar fieldstructure for the symmetric reconnection. Nevertheless,the locality of the satellites constrains the investigation
capability of the global view, making it a challenge tofurther understand the three-dimensional (3D) structuresof the Hall magnetic field in the dayside magnetic
reconnection process for the magnetosphere coupled withIMFs of various orientations.
The Space Plasma Environment Research Facility(SPERF) has been built at the Harbin Institute ofTechnology in China as a “ mini-magnetosphere” forexperimentally simulating fundamental plasma physics
processes in the magnetosphere. As a ground-based
experiment facility, SPERF can be a powerful supplement
for investigating the global reconnection structures.
We in this work focus primarily on the Hall fieldstructure analysis for asymmetric reconnection process
based on a Hall MHD model to numerically simulate theglobal 3D reconnection configuration under the topology
and key parameters of SPERF. Our results reveal that thereconnection structure of 3D null point also features a Hallquadrupolar field, with its projection along the separator
line corresponding to a typical 2D quadrupolar pattern.
Figure 1 illustrates the 3D global reconnection topology
for a “southward IMF” drive with a dawn-dusk
component (Fig. 1(a)), and the corresponding Hall fieldstructure at the reconnection region (Fig. 1(b) and Fig.
1(c)). It indicates that the fan surface with different typesof nulls (A-type or B-type nulls) correspond to Hall fields
of different polarities. Our research contributes to a deeper
understanding of the relationship between 2D and 3D Hall
field structures.

Figure 1. (a)The 3D view of the topological structure for a “southward IMF” drive with a dawn-dusk
component; (b) the local hall magnetic field structure for the A null in Fig. 1 (a); (c) the local hallmagnetic field structure for the B null in Fig. 1 (a).