Properties of asymmetric magnetic reconnection

Journal Article · Sat Mar 15 04:00:00 EDT 2008 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2888491· OSTI ID:21106148

Birn, J; Borovsky, J E ^[1]; Hesse, M ^[2]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2. NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

Properties of magnetic reconnection are investigated in two-dimensional, resistive magnetohydrodynamic (MHD) simulations of current sheets separating plasmas with different magnetic field strengths and densities. Specific emphasis is on the influence of the external parameters on the reconnection rate. The effect of the dissipation in the resistive MHD model is separated from this influence by evaluating resistivity dependence together with the dependence on the background parameters. Two scenarios are considered, which may be distinguished as driven and nondriven reconnection. In either scenario, the maximum reconnection rate (electric field) is found to depend on appropriate hybrid expressions based on a magnetic field strength and an Alfven speed derived from the characteristic values in the two inflow regions. The scaling compares favorably with an analytic formula derived recently by Cassak and Shay [Phys. Plasmas 14, 102114 (2007)] applied to the regime of fast reconnection. An investigation of the energy flow and conversion in the vicinity of the reconnection site revealed a significant role of enthalpy flux generation, in addition to the expected conversion of Poynting flux to kinetic energy flux. This enthalpy flux generation results from Ohmic heating as well as adiabatic, that is, compressional heating. The latter is found more important when the magnetic field strengths in the two inflow regions are comparable in magnitude.

• OSTI ID: 21106148
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 3 Vol. 15; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALFVEN WAVES
ASYMMETRY
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
CURRENTS
ELECTRIC FIELDS
ENTHALPY
JOULE HEATING
KINETIC ENERGY
MAGNETIC FIELDS
MAGNETIC RECONNECTION
MAGNETOHYDRODYNAMICS
PLASMA
PLASMA SIMULATION
TWO-DIMENSIONAL CALCULATIONS