TITLE

Reconnection in compressible plasmas: Extended conversion region

AUTHOR(S)
Birn, J.; Hesse, M.; Zenitani, S.
PUB. DATE
November 2011
SOURCE
Physics of Plasmas;Nov2011, Vol. 18 Issue 11, p111202
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
The classical Sweet-Parker approach to steady-state magnetic reconnection is extended into the regime of large resistivity (small magnetic Reynolds or Lundquist number) when the aspect ratio between the outflow and inflow scale, δ = d/L, approaches unity. In a previous paper [Paper I, Hesse et al., Phys. Plasmas 18, 042104 (2011)], the vicinity of the dissipation site ('diffusion region') was investigated. In this paper, the approach is extended to cover larger sites, in which the energy transfer and conversion is not confined to the diffusion region. Consistent with the results of Paper I, we find that increasing aspect ratio δ is associated with increasing compression, increasing reconnection rate for low β, but slightly decreasing rate for higher β, decreasing outflow speed, and increasing outflow magnetic field. These trends are stronger for lower β. Deviations from the traditional Sweet-Parker limit δ → 0 become significant for Rm<~10, where Rm is the magnetic Reynolds number (Lundquist number) based on the half-thickness of the current layer responsible for the Ohmic dissipation. They are also more significant for small γ, that is, for increasing compressibility. In contrast to the results of Paper I, but consistent with earlier results for δ<1, we find that in this limit the outflow speed is given by the Alfvén speed νA in the inflow region and the energy conversion is given by an even split of Poynting flux into enthalpy flux and bulk kinetic energy flux. However, with increasing δ the conversion to enthalpy flux becomes more and more dominant.
ACCESSION #
67538250

 

Related Articles

  • Numerical study of nonlinear forced magnetic reconnection. Browning, P. K.; Kawaguchi, J.; Kusano, K.; Vekstein, G. E. // Physics of Plasmas;Jan2001, Vol. 8 Issue 1, p132 

    Two-dimensional numerical simulations are used to investigate nonlinear aspects of forced magnetic reconnection in a zero β highly conducting plasma. This is representative of the solar corona, where reconnection may be induced by external perturbations, e.g., at the photospheric boundary of...

  • Magnetic reconnection in a compressible MHD plasma. Hesse, Michael; Birn, Joachim; Zenitani, Seiji // Physics of Plasmas;Apr2011, Vol. 18 Issue 4, p042104 

    Using steady-state resistive MHD, magnetic reconnection is reinvestigated for conditions of high resistivity/low magnetic Reynolds number, when the thickness of the diffusion region is no longer small compared to its length. Implicit expressions for the reconnection rate and other reconnection...

  • Comment on "On the correspondence between forced magnetic reconnection and Alfvén resonances" [Phys. Plasmas 7, 3808 (2000)]. Uberoi, C. // Physics of Plasmas;Jul2001, Vol. 8 Issue 7, p3523 

    In a recent paper Vekstein [Phys. Plasmas 7, 3808 (2000)] argued that the correspondence between the forced magnetic reconnection based on Alfvén resonance theory given by Uberoi and Zweibel [J. Plasma Physics 62, 345 (1999)] is not true. It is shown that the argument by Vekstein based on the...

  • Dissipation scales in the Earth's plasma sheet estimated from Cluster measurements. Vörös, Z.; Baumjohann, W.; Nakamura, R.; Runov, A.; Volwerk, M.; Schwarzl, H.; Balogh, A.; Rème, H.; Vassiliadis, D.; Treumann, R. // Nonlinear Processes in Geophysics;2005, Vol. 12 Issue 5, p725 

    In order to estimate the dissipation time-scale in magnetic turbulence in the plasma sheet a novel method is introduced for classification of velocity dependent patterns of two-point probability density functions' shapes near their maxima. For the first time, we provide evidence for Reynolds...

  • Magnetic Reconnection Phenomena In Interplanetary Space. Fengsi Wei; Qiang Hu; Xueshang Feng; Quanlin Fan // Space Science Reviews;Mar2003, Vol. 107 Issue 1/2, p107 

    Interplanetary magnetic reconnection(IMR) phenomena are explored based on the observational data with various time resolutions from Helios, IMP-8, ISEE3, Wind, etc. We discover that the observational evidence of the magnetic reconnection may be found in the various solar wind structures, such as...

  • Dissipation in relativistic pair-plasma reconnection. Hesse, Michael; Zenitani, Seiji // Physics of Plasmas;Nov2007, Vol. 14 Issue 11, p112102 

    An investigation into the relativistic dissipation in magnetic reconnection is presented. The investigated system consists of an electron-positron plasma. A relativistic generalization of Ohm’s law is derived. A set of numerical simulations is analyzed, composed of runs with and without...

  • Anisotropic dissipative effects on the buoyancy instability with background heat flux. Ren, Haijun; Cao, Jintao; Wu, Zhengwei; Chu, Paul K. // Physics of Plasmas;Mar2011, Vol. 18 Issue 3, p032106 

    The linear buoyancy instability in magnetized plasmas is investigated in the presence of anisotropic resistivity and viscosity by taking into account the background heat flux. The magnetic field is assumed to be homogeneous and has both horizontal and vertical components. The heat is primarily...

  • Computer studies on the fast reconnection mechanism under an externally driven boundary condition. Ugai, M. // Physics of Plasmas;Sep94, Vol. 1 Issue 9, p2853 

    Reports on a computer simulations study of the temporal dynamics of magnetic reconnection in a current sheet system under a continuous local plasma injection imposed on the inflow boundary. Influenced of the resistivity model on the basic reconnection process; Drastic occurrence of magnetic...

  • Role of compressibility on driven magnetic reconnection. Sato, T.; Hayashi, T.; Watanabe, K.; Horiuchi, R.; Tanaka, M.; Sawairi, N.; Kusano, K. // Physics of Fluids B: Plasma Physics;Feb92, Vol. 4 Issue 2, p450 

    Whether it is induced by an ideal (current driven) instability or by an external force, plasma flow causes a change in the magnetic field configuration and often gives rise to a current intensification locally, thereby a fast driven reconnection being driven there. Many dramatic phenomena in...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

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

Try another library?
Sign out of this library

Other Topics