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Title: A two-fluid study of oblique tearing modes in a force-free current sheet

Kinetic simulations have demonstrated that three-dimensional reconnection in collisionless regimes proceeds through the formation and interaction of magnetic flux ropes, which are generated due to the growth of tearing instabilities at multiple resonance surfaces. Since kinetic simulations are intrinsically expensive, it is desirable to explore the feasibility of reduced two-fluid models to capture this complex evolution, particularly, in the strong guide field regime, where two-fluid models are better justified. With this goal in mind, this paper compares the evolution of the collisionless tearing instability in a force-free current sheet with a two-fluid model and fully kinetic simulations. Our results indicate that the most unstable modes are oblique for guide fields larger than the reconnecting field, in agreement with the kinetic results. The standard two-fluid tearing theory is extended to address the tearing instability at oblique angles. The resulting theory yields a flat oblique spectrum and underestimates the growth of oblique modes in a similar manner to kinetic theory relative to kinetic simulations.
Authors:
;  [1] ;  [2] ;  [3]
  1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
  2. National Science Foundation, Arlington, Virginia 22230 (United States)
  3. NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)
Publication Date:
OSTI Identifier:
22493810
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 23; Journal Issue: 1; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COLLISIONLESS PLASMA; KINETIC EQUATIONS; LANDAU LIQUID HELIUM THEORY; MAGNETIC FLUX; MAGNETIC RECONNECTION; PLASMA SIMULATION; RESONANCE; SPECTRA; TEARING INSTABILITY; THREE-DIMENSIONAL CALCULATIONS