Magnetic reconnection in a weakly ionized plasma

Journal Article · Sat Jun 15 00:00:00 EDT 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4811140· OSTI ID:22228002

Leake, James E. ^[1]; Lukin, Vyacheslav S.; Linton, Mark G. ^[2]

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1. College of Science, George Mason University, 4400 University Drive, Fairfax, Virginia 22030 (United States)
2. U.S. Naval Research Lab, 4555 Overlook Ave., SW Washington, DC 20375 (United States)

Magnetic reconnection in partially ionized plasmas is a ubiquitous phenomenon spanning the range from laboratory to intergalactic scales, yet it remains poorly understood and relatively little studied. Here, we present results from a self-consistent multi-fluid simulation of magnetic reconnection in a weakly ionized reacting plasma with a particular focus on the parameter regime of the solar chromosphere. The numerical model includes collisional transport, interaction and reactions between the species, and optically thin radiative losses. This model improves upon our previous work in Leake et al.[“Multi-fluid simulations of chromospheric magnetic reconnection in a weakly ionized reacting plasma,” Astrophys. J. 760, 109 (2012)] by considering realistic chromospheric transport coefficients, and by solving a generalized Ohm's law that accounts for finite ion-inertia and electron-neutral drag. We find that during the two dimensional reconnection of a Harris current sheet with an initial width larger than the neutral-ion collisional coupling scale, the current sheet thins until its width becomes less than this coupling scale, and the neutral and ion fluids decouple upstream from the reconnection site. During this process of decoupling, we observe reconnection faster than the single-fluid Sweet-Parker prediction, with recombination and plasma outflow both playing a role in determining the reconnection rate. As the current sheet thins further and elongates, it becomes unstable to the secondary tearing instability, and plasmoids are seen. The reconnection rate, outflows, and plasmoids observed in this simulation provide evidence that magnetic reconnection in the chromosphere could be responsible for jet-like transient phenomena such as spicules and chromospheric jets.

• OSTI ID: 22228002
• Journal Information: Physics of Plasmas, Vol. 20, Issue 6; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTROPHYSICS
CHROMOSPHERE
ELECTRONS
IONIZATION
IONS
MAGNETIC RECONNECTION
MAGNETOHYDRODYNAMICS
MOMENT OF INERTIA
NUMERICAL ANALYSIS
OHM LAW
PLASMA
PLASMA JETS
PLASMA SIMULATION
PLASMOIDS
RECOMBINATION
TEARING INSTABILITY
TWO-DIMENSIONAL CALCULATIONS