Energy transfer and electron energization in collisionless magnetic reconnection for different guide-field intensities

Abstract

Electron dynamics and energization are one of the key components of magnetic field dissipation in collisionless reconnection. In 2D numerical simulations of magnetic reconnection, the main mechanism that limits the current density and provides an effective dissipation is most probably the electron pressure tensor term, that has been shown to break the frozen-in condition at the x-point. In addition, the electron-meandering-orbit scale controls the width of the electron dissipation region, where the electron temperature has been observed to increase both in recent Magnetospheric Multiple-Scale (MMS) observations as well as in laboratory experiments, such as the Magnetic Reconnection Experiment (MRX). By means of two-dimensional full-particle simulations in an open system, we investigate how the energy conversion and particle energization depend on the guide field intensity. We study the energy transfer from magnetic field to the plasma, $\mathbf{E}\cdot \mathbf{J}$ and the threshold guide field separating two regimes where either the parallel component, $E_{||}{J}_{||}$, or the perpendicular component, ${\mathbf{E}}_{\perp }\cdot {\mathbf{J}}_{\perp }$, dominate the energy transfer, confirming recent MRX results and also consistent with MMS observations. We calculate the energy partition between fields, kinetic, and thermal energy of different species, from electron to ion scales, showing there is no significant variation for different guide field configurations. Finally we study possible mechanisms for electron perpendicular heating by examining electron distribution functions and self-consistently evolved particle orbits in high guide field configurations.

References in corpus (7)

• New Measure of the Dissipation Region in Collisionless Magnetic Reconnection
• The roles of fluid compression and shear in electron energization during magnetic reconnection
• Electromagnetic Energy Conversion in Downstream Fronts from 3D Kinetic Reconnection
• The effect of a guide field on local energy conversion during asymmetric magnetic reconnection: MMS observations
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• Particle dynamics in the electron current layer in collisionless magnetic reconnection
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Cited by in corpus (5)

• Statistical properties of magnetic structures and energy dissipation during turbulent reconnection in the Earth's magnetotail
• Energy transport during 3D small-scale reconnection driven by anisotropic plasma turbulence
• Anisotropic Heating and Parallel Heat Flux in Electron-only Magnetic Reconnection with Intense Guide Fields
• Characterizing Velocity-Space Signatures of Electron Energization in Large-Guide-Field Collisionless Magnetic Reconnection
• Anisotropic electron heating in turbulence-driven magnetic reconnection in the near-Sun solar wind