A new fast reconnection model in a collisionless regime

Tsiklauri, David
November 2008
Physics of Plasmas;11/1/2008, Vol. 15 Issue 11, p112903
Academic Journal
Based on the first principles [i.e., (i) by balancing the magnetic field advection with the term containing electron pressure tensor nongyrotropic components in the generalized Ohm’s law; (ii) using the conservation of mass; and (iii) assuming that the weak magnetic field region width, where electron meandering motion supports electron pressure tensor off-diagonal (nongyrotropic) components, is of the order of electron Larmor radius] a simple model of magnetic reconnection in a collisionless regime is formulated. The model is general, resembling its collisional Sweet–Parker analog in that it is not specific to any initial configuration, e.g., Harris-type tearing unstable current sheet, X-point collapse or otherwise. In addition to its importance from the fundamental point of view, the collisionless reconnection model offers a much faster reconnection rate [Mc′less=(c/ωpe)2/(rL,eL)] than Sweet–Parker’s classical one (Msp=S-1/2). The width of the diffusion region (current sheet) in the collisionless regime is found to be δc′less=(c/ωpe)2/rL,e, which is independent of the global reconnection scale L and is only prescribed by microphysics (electron inertial length, c/ωpe, and electron Larmor radius, rL,e). Amongst other issues, the fastness of the reconnection rate alleviates, e.g., the problem of interpretation of solar flares by means of reconnection, as for the typical solar coronal parameters the obtained collisionless reconnection time can be a few minutes, as opposed to Sweet–Parker’s equivalent value of less than a day. The new theoretical reconnection rate is compared to the Magnetic Reconnection Experiment device experimental data by Yamada et al. [Phys. Plasmas 13, 052119 (2006)] and Ji et al. [Geophys. Res. Lett. 35, 13106 (2008)], and a good agreement is obtained.


Related Articles

  • Magnetic Reconnection and Particle Acceleration at Earth’s Dayside Magnetopause: Results from Global Simulations. Berchem, Jean; Richard, Robert // AIP Conference Proceedings;8/25/2008, Vol. 1039 Issue 1, p301 

    We review recent progress in the large-scale modeling of the topology and dynamics of magnetic reconnection at Earth’s dayside magnetopause. We use three-dimensional global magnetohydrodynamic (MHD) and large-scale kinetic (LSK) simulations to analyze reconnection events observed by...

  • Magnetic field reconnection: A first-principles perspective. Mozer, Forrest S.; Pritchett, Philip L. // Physics Today;Jun2010, Vol. 63 Issue 6, p34 

    The article discusses the magnetic field reconnection, considering the mechanisms for charged particles acceleration and the reconnection between solar and terrestrial magnetic field lines. It says that magnetic field reconnection takes place when 2 magnetized plasmas flow near each other. It...

  • Generalized magnetofluid connections in pair plasmas. Asenjo, Felipe A.; Comisso, Luca; Mahajan, Swadesh M. // Physics of Plasmas;Dec2015, Vol. 22 Issue 12, p1 

    We extend the magnetic connection theorem of ideal magnetohydrodynamics to nonideal relativistic pair plasmas. Adopting a generalized Ohm's law, we prove the existence of generalized magnetofluid connections that are preserved by the plasma dynamics. We show that these connections are related to...

  • Forced Hall magnetic reconnection: Parametric variation of the “Newton Challenge”. Huba, J. D. // Physics of Plasmas;Jun2006, Vol. 13 Issue 6, p062311 

    A parametric study of forced magnetic reconnection using a 2D Hall magnetohydrodynamic (MHD) code based on the “Newton Challenge” is presented. The “Newton Challenge” defined a magnetic reconnection problem in which reconnection was initiated by a spatially and temporally...

  • Particle Acceleration in the Magnetotail and Aurora. Birn, J.; Artemyev, A.; Baker, D.; Echim, M.; Hoshino, M.; Zelenyi, L. // Space Science Reviews;Nov2012, Vol. 173 Issue 1-4, p49 

    This paper deals with acceleration processes in the magnetotail and the processes that enhance particle precipitation from the tail into the ionosphere through electric fields in the auroral acceleration region, generating or intensifying discrete auroral arcs. Particle acceleration in the...

  • Time evolution of the electron diffusion region and the reconnection rate in fully kinetic and large system. Fujimoto, Keizo // Physics of Plasmas;Jul2006, Vol. 13 Issue 7, p072904 

    Time evolutions of the electron diffusion region embedded in the ion-scale diffusion region and the reconnection rate associated with magnetic reconnection are investigated using 2-1/2 dimensional full kinetic simulations in a large system, so that any effects of the downstream boundary...

  • Flux and Field Line Conservation in 3-D Non-Ideal MHD Flows: Remarks About Criteria for 3-D Reconnection Without Magnetic Neutral Points and Their Application to the Heliospheric Interface. Nickeler, D. H.; Fahr, H.-J. // Solar Physics;May2006, Vol. 235 Issue 1/2, p191 

    In this paper, we address the issue of finding velocity fields which conserve magnetic flux or at least magnetic fieldline connectivity. We start from the basic principles of flux and line conservation and present and discuss the criterion, given by Newcomb (1958), Stern (1966), and Vasyliunas...

  • Magnetic Reconnection Solutions Based on a Generalized Ohm's law. Craig, I. J. D.; Watson, P. G. // Solar Physics;May2003, Vol. 214 Issue 1, p131 

    It is known that exact magnetic reconnection solutions can be constructed for collisionally dominated resistive plasmas. In this paper we refine the collisional resistive description by invoking an Ohm's law that includes Hall current and plasma inertial contributions. We first demonstrate the...

  • Measurements of impulsive reconnection driven by nonlinear Hall dynamics. Tharp, T. D.; Almagri, A. F.; Miller, M. C.; Mirnov, V. V.; Prager, S. C.; Sarff, J. S.; Kim, C. C. // Physics of Plasmas;Dec2010, Vol. 17 Issue 12, p120701 

    The magnetic fields associated with reconnection in the edge of the reversed field pinch configuration have been measured in the Madison Symmetric Torus. The measured magnetic field structure is compared with theoretical predictions computed in both toroidal and cylindrical geometries. The...


Read the Article


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

Try another library?
Sign out of this library

Other Topics