A particle simulation of current sheet instabilities under finite guide field

Journal Article · Tue Jul 15 04:00:00 EDT 2008 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2938732· OSTI ID:21268932

Wang, X Y; Lin, Y ^[1]; Chen, L ^[2]; Lin, Z ^[2]

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1. Department of Physics, Auburn University, Auburn, Alabama 36849 (United States)
2. Department of Physics and Astronomy, University of California at Irvine, Irvine, California 92697 (United States)

The instability of a Harris current sheet under a broad range of finite guide field (B{sub G}) is investigated using a linearized ({delta}f) gyrokinetic electron and fully kinetic ion particle simulation code. The simulation is carried out in the two-dimensional plane containing the guide field along y and the current sheet normal along z. In this particle model, the rapid electron cyclotron motion is removed, while the realistic mass ratio m{sub i}/m{sub e}, finite electron Larmor radii, and wave-particle interactions are kept. It is found that for a finite B{sub G}/B{sub x0}{<=}1, where B{sub x0} is the asymptotic antiparallel component of magnetic field, three unstable modes, i.e., modes A, B, and C, can be excited in the current sheet. Modes A and C, appearing to be quasielectrostatic modified two-stream instability/whistler mode, are located mainly on the edge of the current sheet. Mode B, on the other hand, is confined in the current sheet center and carries a compressional magnetic field ({delta}B{sub y}) perturbation along the direction of electron drift velocity. Our new finding suggests that mode B may contribute directly to the electron anomalous resistivity in magnetic reconnection. In the cases with extremely large B{sub G}/B{sub x0}>>1, the wave modes evolve to a globally propagating instability. The simulation shows that the presence of finite B{sub G} modifies the physics of the current sheet significantly.

• OSTI ID: 21268932
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 7 Vol. 15; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CURRENTS
ELECTRON DRIFT
ELECTRONS
LARMOR RADIUS
MAGNETIC RECONNECTION
MAGNETOHYDRODYNAMICS
PLASMA
PLASMA SIMULATION
TWO-DIMENSIONAL CALCULATIONS
TWO-STREAM INSTABILITY
WHISTLER INSTABILITY