Dissipation in magnetic reconnection with a guide magnetic field
Abstract
A combination of numerical simulation results and analytical theory is applied to the problem of magnetic reconnection in a guide magnetic field. An investigation of electron distribution functions within the electron diffusion region leads to a picture of mixing of particles with different acceleration histories on electron Larmor scales. Based on an apparent average loss of accelerated particles by fieldaligned and ExB transport, it is proposed that the role of the reconnection electric field is to replenish this loss by acceleration of particles that enter the electron diffusion region. Analytic theory is employed to verify this model, and an equation is derived, which balances the average electric field force density by a diffusion term applied to the electron momentum density. The diffusion coefficient contains explicitly the electron Larmor spatial scale and a poloidal transport time scale.
 Authors:
 NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)
 Publication Date:
 OSTI Identifier:
 20860424
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physics of Plasmas; Journal Volume: 13; Journal Issue: 12; Other Information: DOI: 10.1063/1.2403784; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ACCELERATION; COMPUTERIZED SIMULATION; DIFFUSION; DISTRIBUTION FUNCTIONS; ELECTRIC FIELDS; ELECTROMAGNETIC FIELDS; ELECTRONS; MAGNETIC FIELDS; MAGNETIC RECONNECTION; MAGNETOHYDRODYNAMICS; NUMERICAL ANALYSIS; PLASMA; PLASMA DENSITY; PLASMA SIMULATION; RADIATION TRANSPORT
Citation Formats
Hesse, Michael. Dissipation in magnetic reconnection with a guide magnetic field. United States: N. p., 2006.
Web. doi:10.1063/1.2403784.
Hesse, Michael. Dissipation in magnetic reconnection with a guide magnetic field. United States. doi:10.1063/1.2403784.
Hesse, Michael. Fri .
"Dissipation in magnetic reconnection with a guide magnetic field". United States.
doi:10.1063/1.2403784.
@article{osti_20860424,
title = {Dissipation in magnetic reconnection with a guide magnetic field},
author = {Hesse, Michael},
abstractNote = {A combination of numerical simulation results and analytical theory is applied to the problem of magnetic reconnection in a guide magnetic field. An investigation of electron distribution functions within the electron diffusion region leads to a picture of mixing of particles with different acceleration histories on electron Larmor scales. Based on an apparent average loss of accelerated particles by fieldaligned and ExB transport, it is proposed that the role of the reconnection electric field is to replenish this loss by acceleration of particles that enter the electron diffusion region. Analytic theory is employed to verify this model, and an equation is derived, which balances the average electric field force density by a diffusion term applied to the electron momentum density. The diffusion coefficient contains explicitly the electron Larmor spatial scale and a poloidal transport time scale.},
doi = {10.1063/1.2403784},
journal = {Physics of Plasmas},
number = 12,
volume = 13,
place = {United States},
year = {Fri Dec 15 00:00:00 EST 2006},
month = {Fri Dec 15 00:00:00 EST 2006}
}

A numerical study of guidefield magnetic reconnection in a threedimensional model is presented. Starting from an initial, perturbed, forcefree current sheet, it is shown that reconnection develops to an almost translationally invariant state, where magnetic perturbations are aligned primarily along the main current flow direction. An analysis of guidefield and electron flow signatures indicates behavior that is very similar to earlier, albeit not threedimensional, simulations. Furthermore, a detailed investigation of electron pressure nongyrotropies in the central diffusion region confirms the major role the associated dissipation process plays in establishing the reconnection electric field.

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