Hall assisted forced magnetic reconnection

Journal Article · Fri Dec 15 04:00:00 EST 2006 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2398933· OSTI ID:20860422

Vekstein, G; Bian, N H ^[1]

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1. School of Physics and Astronomy, University of Manchester, Manchester M60 1QD (United Kingdom)

The role of the Hall effect in forced magnetic reconnection is investigated analytically for the so-called Taylor problem. In the latter, a tearing stable slab plasma equilibrium, which is chosen here to be a simple magnetic field reversal, is subjected to a small-amplitude boundary deformation that drives magnetic reconnection (hence the adjective 'forced') at the neutral surface within the plasma. It is shown that such reconnection becomes substantially accelerated by the Hall effect when the nondimensional parameter d{sub i}=(c/{omega}{sub pi})/a exceeds S{sup -1/5}. Here, c/{omega}{sub pi} is the ion inertial skin depth, a is the width of the plasma slab, and S>>1 is the Lundquist number of a highly conducting plasma. Two different types of external perturbation are considered. In the case of continuous quasistatic driving, with a frequency {omega} such that {omega}{tau}{sub A}<<1, {tau}{sub A} being the Alfven transit time, various reconnection regimes are identified. The corresponding heating rates, which are determined by the parameters d{sub i}, S, and {omega}{tau}{sub A}, are derived. In the case of a 'one-off' reconnection event, we demonstrate when and how the transition from the Hall regime to the magnetohydrodynamic regime occurs in the course of the reconnection process. It is found that the peak instantaneous reconnection rate scales as d{psi}{sub 1}(0)/dt{approx}d{sub i}{sup 1/2}S{sup -1/2}(B{sub 0}{delta}{sub 0}/{tau}{sub A}), where {psi}{sub 1}(0) is the reconnected magnetic flux, B{sub 0} is the magnetic field strength, and {delta}{sub 0} is the amplitude of the boundary deformation.

• OSTI ID: 20860422
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 12 Vol. 13; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALFVEN WAVES
AMPLITUDES
BOUNDARY LAYERS
DEFORMATION
DISTURBANCES
EQUILIBRIUM
HALL EFFECT
HEATING RATE
MAGNETIC FIELD REVERSAL
MAGNETIC FIELDS
MAGNETIC FLUX
MAGNETIC RECONNECTION
MAGNETOHYDRODYNAMICS
PLASMA
RADIATION TRANSPORT
TEARING INSTABILITY