TITLE

Fundamental role of ion viscosity on fast magnetic reconnection in large-guide-field regimes

AUTHOR(S)
Simakov, Andrei N.; Chacón, L.; Zocco, A.
PUB. DATE
June 2010
SOURCE
Physics of Plasmas;Jun2010, Vol. 17 Issue 6, p060701
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Nonlinear analytical theory of magnetic reconnection with a large guide field is presented for the first time. We confirm that two distinct steady-state reconnection regimes are possible depending on the relative size of the diffusion region thickness δ versus the sound gyroradius ρs. The reconnection is slow (Sweet–Parker-like) for δ>=ρs, and fast otherwise. However, unlike earlier work, we find that ion viscosity μ plays a fundamental role in the fast regime. In particular, for δ<ρs we obtain δ∝Ha-1, with Ha∝1/ημ as the Hartmann number, and the reconnection rate Ez∝Pr-1/2, with Pr=μ/η as the Prandtl number and η as the resistivity. If the perpendicular ion viscosity is employed for μ, the reconnection rate becomes independent of plasma β and collision frequencies, and therefore potentially fast.
ACCESSION #
51848479

 

Related Articles

  • Magnetic reconnection in electron magnetohydrodynamics. Bulanov, S. V.; Pegoraro, F.; Sakharov, A. S. // Physics of Fluids B: Plasma Physics;Aug92, Vol. 4 Issue 8, p2499 

    The magnetic field dynamics and reconnection processes in a highly conducting plasma are investigated in the regimes where Ohm’s law is dominated by the Hall term, using a single (electron) fluid description (electron magnetohydrodynamics). In these regimes, which correspond to the...

  • Computer studies on the spontaneous fast reconnection evolution in various physical situations. Ugai, M.; Kondoh, K. // Physics of Plasmas;May2001, Vol. 8 Issue 5, p1545 

    The spontaneous fast reconnection evolution is studied in a long current sheet system in various physical situations, where the threshold of current-driven anomalous resistivity is assumed to increase with the thermal velocity. If the initial threshold V[sub co] is sufficiently large in a...

  • Fast reconnection in high temperature plasmas. Kleva, Robert G.; Drake, J. F. // Physics of Plasmas;Jan1995, Vol. 2 Issue 1, p23 

    Demonstrates how pressure forces acting on electrons dramatically alter magnetic field line reconnection in high temperature plasmas. Physical scale length; Ion gyroradius based on the electron temperature; Resistive magnetohydrodynamic equations; Single dissipation layer of resistive MHD.

  • Three-dimensional evolution of the fast reconnection mechanism in a force-free current sheet. Ugai, M. // Physics of Plasmas;Jun2010, Vol. 17 Issue 6, p062901 

    As a sequence of the recent paper on the fast reconnection evolution in a sheared current sheet [M. Ugai, Phys. Plasmas 17, 032313 (2010)], the present paper further studies the three-dimensional fast reconnection evolution in a force-free current sheet system. In general, for the larger sheared...

  • An electromagnetic drift instability in the magnetic reconnection experiment and its importance for magnetic reconnection. Kulsrud, Russell; Hantao Ji; Fox, William; Yamada, Masaaki // Physics of Plasmas;Aug2005, Vol. 12 Issue 8, p082301 

    The role which resistivity plays in breaking magnetic field lines, heating the plasma, and plasma-field slippage during magnetic reconnection is discussed. Magnetic fluctuations are observed in the MRX (magnetic reconnection experiment) [M. Yamada, H. Ji, S. Hsu, T. Carter, R. Kulsrud, N. Bertz,...

  • Spectral scaling in the turbulent Earth's plasma sheet revisited. Vörös, Z.; Baumjohann, W.; Nakamura, R.; Runov, A.; Volwerk, M.; Asano, Y.; Jankovičová, D.; Lucek, E. A.; Rème, H. // Nonlinear Processes in Geophysics;2007, Vol. 14 Issue 4, p535 

    Bursty bulk flow associated magnetic fluctuations exhibit at least three spectral scaling ranges in the Earth's plasma sheet. Two of the three scaling ranges can be associated with multi-scale magnetohydrodynamic turbulence between the spatial scales from ~100 km to several RE (RE is the Earth's...

  • Experimental evidence of fast reconnection via trapped electron motion. Egedal, J.; Fox, W.; Porkolab, M.; Fasoli, A. // Physics of Plasmas;May2004, Vol. 11 Issue 5, p2844 

    Magnetic reconnection in collisionless magnetohydrodynamic plasmas is studied under controlled conditions in toroidal X-line configurations formed in the center of the Versatile Toroidal Facility [J. Egedal et al., Rev. Sci. Instrum. 71, 3351 (2000)]. Profiles of key parameters are measured...

  • Interplay between Magnetic Reconnection and the Kelvin-Helmholtz and Rayleigh-Taylor Instabilities in a Magnetized Inhomogeneous Plasma with a Velocity Shear. Faganello, M.; Califano, F.; Pegoraro, F. // AIP Conference Proceedings;10/15/2008, Vol. 1061 Issue 1, p217 

    The competition between instabilities in a plasma can lead to qualitatively different configurations that can be observed experimentally. The outcome of this competition gives us important clues about the time development of these instabilities as we can use one to clock the development of the...

  • Magnetic reconnection with Sweet-Parker characteristics in two-dimensional laboratory plasmas. Hantao Ji; Yamada, Masaaki; Hsu, Scott; Kulsrud, Russell; Carter, Troy; Zaharia, Sorin // Physics of Plasmas;May99, Vol. 6 Issue 5, p1743 

    Magnetic reconnection has been studied experimentally in a well-controlled, two-dimensional laboratory magnetohydrodynamic plasma. The observations are found to be both qualitatively and quantitatively consistent with a generalized Sweet-Parker model which incorporates compressibility,...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics