On the instability of a quasiequilibrium current sheet and the onset of impulsive bursty reconnection

Skender, Marina; Lapenta, Giovanni
February 2010
Physics of Plasmas;Feb2010, Vol. 17 Issue 2, p022905
Academic Journal
A two-dimensional reconnecting current sheet is studied numerically in the magnetohydrodynamic approach. Different simulation setups are employed in order to follow the evolution of the formed current sheet in diverse configurations: two types of initial equilibria, Harris and force-free, two types of boundary conditions, periodic and open, with uniform and nonuniform grid set, respectively. All the simulated cases are found to exhibit qualitatively the same behavior in which a current sheet evolves slowly through a series of quasiequilibria; eventually it fragments and enters a phase of fast impulsive bursty reconnection. In order to gain more insight on the nature and characteristics of the instability taking place, physical characteristics of the simulated current sheet are related to its geometrical properties. At the adopted Lundquist number of S=104 and Reynolds number R=104, the ratio of the length to width (aspect ratio) of the formed current sheet is observed to increase slowly in time up to a maximum value at which it fragments. Moreover, additional turbulence applied to the system is shown to exhibit the same qualitative steps, but with the sooner onset of the fragmentation and at smaller aspect ratio.


Related Articles

  • Boundary instability of a two-dimensional electron fluid. Dyakonov, M. I. // Semiconductors;Aug2008, Vol. 42 Issue 8, p984 

    It was shown previously that the current-carrying state of a Field Effect Transistor with asymmetric source and drain boundary conditions may become unstable against spontaneous generation of plasma waves [1]. By extending the analysis to the two-dimensional case we find that the dominant...

  • Large-eddy simulation of magnetohydrodynamic turbulence in compressible fluid. Chernyshov, A. A.; Karelsky, K. V.; Petrosyan, A. S. // Physics of Plasmas;Mar2006, Vol. 13 Issue 3, p032304 

    In the present article, the large eddy simulation (LES) technique for the study of compressible magnetohydrodynamic turbulence is developed. The filtered equations of magnetohydrodynamics of compressible fluid are obtained with the use of a mass-weighted filtering procedure (Favre filtering)....

  • MHD FLOW AND HEAT TRANSFER NEAR THE STAGNATION POINT ON A STRETCHING/SHRINKING SHEET IN A MICROPOLAR FLUID. Bachok, N.; Ishak, A.; Pop, I. // Magnetohydrodynamics (0024-998X);Jul-Sep2011, Vol. 47 Issue 3, p237 

    The problem of two-dimensional magnetohydrodynamic (MHD) stagnation point flow of an incompressible micropolar fluid over a stretching/shrinking sheet is studied. The governing continuity, momentum, angular momentum and heat equations together with the associated boundary conditions are...

  • Detector array for measurement of high-frequency fluctuations in visible and near-UV emission from tokamaks. Hurwitz, P. D.; Hall, B. F.; Rowan, William L. // Review of Scientific Instruments;Oct92, Vol. 63 Issue 10, p4614 

    We developed an imaging detector to measure high-frequency fluctuations in visible and near-UV emission from tokamaks. The detector is intended for the study of plasma turbulence, mhd phenomena, and edge-localized modes. Particularly in the first two applications, it will complement existing...

  • Finite Larmor radius stabilization of the Rayleigh--Taylor turbulent mixing width. Mikaelian, Karnig O. // Physics of Plasmas;Feb97, Vol. 4 Issue 2, p499 

    Investigates the finite Larmor radius stabilization of the Rayleigh-Taylor turbulent mixing width. Comparison of a diffusion model with two-dimensional magnetohydrodynamic simulations; Density gradient stabilization; Agreement with Huba's numerical simulations.

  • Statistical analysis of turbulent flux and intermittency in the nonfusion magnetoplasma Blaamann. Fredriksen, A.; Riccardi, C.; Cartegni, L.; Draghi, D.; Trasarti-Battistoni, R.; Roman, H.E. // Physics of Plasmas;Nov2003, Vol. 10 Issue 11, p4335 

    Turbulent particle flux due to correlated fluctuations of density and Evector ×Bvector -drift velocity has been statistically characterized in the simple magnetized torus Blaamann [F. J. O\ynes, O. M. Olsen, H. L. Pécseli, A. Fredriksen, and K. Rypdal, Phys. Rev. E 57, 2242 (1998)]. The...

  • Magnetohydrodynamic equilibrium and stability of rotating plasmas in a mirror geometry. Aydemir, A. Y. // Physics of Plasmas;Nov2004, Vol. 11 Issue 11, p5065 

    A systematic study of equilibrium and stability of rotating plasmas in a mirror geometry is presented. At supersonic azimuthal rotation velocities, centrifugal forces lead to equilibria with nearly detached plasmas, where the plasma mass concentrates at the mirror center. However, isolation of...

  • On apparent temperature in low-frequency Alfvénic turbulence. Nariyuki, Yasuhiro // Physics of Plasmas;Aug2012, Vol. 19 Issue 8, p084504 

    Low-frequency, parallel propagating Alfvénic turbulence in collisionless plasmas is theoretically studied. Alfvénic turbulence is derived as an equilibrium state (Beltrami field) in the magnetohydrodynamic equations with the pressure anisotropy and multi-species of ions. It is shown that...

  • A gyrokinetic ion zero electron inertia fluid electron model for turbulence simulations. Chen, Yang; Parker, Scott // Physics of Plasmas;Feb2001, Vol. 8 Issue 2, p441 

    This paper describes the formulation of a hybrid model with fully gyrokinetic ions and a zero-inertia fluid model for the electrons. The electron fluid equations are derived from moments of the drift kinetic equation, taking the small mass ratio limit, but with finite electron temperature. This...


Read the Article


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

Try another library?
Sign out of this library

Other Topics