Fast Magnetic Reconnection Due to Anisotropic Electron Pressure

Abstract

A new regime of fast magnetic reconnection with an out-of-plane (guide) magnetic field is reported in which the key role is played by an electron pressure anisotropy described by the Chew-Goldberger-Low gyrotropic equations of state in the generalized Ohm's law, which even dominates the Hall term. A description of the physical cause of this behavior is provided and two-dimensional fluid simulations are used to confirm the results. The electron pressure anisotropy causes the out-of-plane magnetic field to develop a quadrupole structure of opposite polarity to the Hall magnetic field and gives rise to dispersive waves. In addition to being important for understanding what causes reconnection to be fast, this mechanism should dominate in plasmas with low plasma beta and a high in-plane plasma beta with electron temperature comparable to or larger than ion temperature, so it could be relevant in the solar wind and some tokamaks.

arXiv comment5 pages, 2 figures, accepted for publication as a letter in Physics of Plasmas

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Cited by in corpus (13)

• Why does steady-state magnetic reconnection have a maximum local rate of order 0.1?
• A Review of the 0.1 Reconnection Rate Problem
• "Ideal" tearing and the transition to fast reconnection in the weakly collisional MHD and EMHD regimes
• Three-Dimensional Stability of Current Sheets Supported by Electron Pressure Anisotropy
• Secondary fast reconnecting instability in the sawtooth crash
• Gyrokinetic and kinetic particle-in-cell simulations of guide-field reconnection. I: Macroscopic effects of the electron flows
• The Force Balance of Electrons During Kinetic Anti-parallel Magnetic Reconnection
• Pressure anisotropy generation in a magnetized plasma configuration with a shear flow velocity
• Hamiltonian kinetic-Hall Magnetohydrodynamics with fluid and kinetic ions in the current and pressure coupling schemes
• Onset of magnetic reconnection in a collisionless, high-beta plasma
• Finite-Larmor-radius equilibrium and currents of the Earth's flank magnetopause
• A Parallel-Kinetic-Perpendicular-Moment Model for Magnetized Plasmas
• Impact of electron temperature anisotropy on the collisionless tearing mode instability in the presence of a strong guide field