Numerical Studies of Tearing Mode Instability and Magnetic Reconnection in Anisotropic Plasma

2001 ◽  
Vol 44 (4) ◽  
pp. 435-443
Author(s):  
Ying-Juan MA ◽  
Shui WANG
Keyword(s):  
Magnetic Reconnection ◽  
Anisotropic Plasma ◽  
Tearing Mode ◽  
Mode Instability ◽  
Numerical Studies

scholarly journals Numerical studies on electron magnetohydrodynamics tearing mode instability

AIP Advances ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 115206
Author(s):  
Wenping Guo ◽  
Jiaqi Wang ◽  
Dongjian Liu
Keyword(s):  
Tearing Mode ◽  
Mode Instability ◽  
Numerical Studies

scholarly journals Current Sheets in Solar Flares

1985 ◽  
Vol 107 ◽  
pp. 233-244
Author(s):  
E. R. Priest
Keyword(s):  
Numerical Simulations ◽  
Magnetic Reconnection ◽  
Solar Flares ◽  
Tearing Mode ◽  
Mode Instability ◽  
Current Sheets ◽  
Magnetic Arcade

Until recently magnetic reconnection in solar flares was discussed simplistically in terms of either a spontaneous tearing mode instability or a driven Petschek mode. Now the subtle relationship between these two extremes is much better understood. Current sheets may form and reconnection may be initiated in many different ways. There are also a variety of nonlinear pathways from a reconnection instability and several types of driven reconnection.In solar flares current sheets may be important as new flux emerges from below the photosphere and also as a magnetic arcade closes down after being blown open by an eruptive instability. Numerical simulations of these sheets will be described, including new features such as the presence of a fast shock in Petschek's mechanism and impulsive bursty reconnection due to secondary tearing and coalescence.

scholarly journals 3D RESISTIVE MHD SIMULATIONS OF MAGNETIC RECONNECTION AND THE TEARING MODE INSTABILITY IN CURRENT SHEETS

2008 ◽  
Vol 17 (10) ◽  
pp. 1715-1721 ◽  
Author(s):  
G. C. MURPHY ◽  
R. OUYED ◽  
G. PELLETIER
Keyword(s):  
Kinetic Energy ◽  
Magnetic Reconnection ◽  
Current Sheet ◽  
Critical Role ◽  
Temporal Stability ◽  
High Energy ◽  
Linear Regime ◽  
Tearing Mode ◽  
Mode Instability ◽  
Mhd Simulations

Magnetic reconnection plays a critical role in many astrophysical processes where high energy emission is observed, e.g. particle acceleration, relativistic accretion powered outflows, pulsar winds and probably in dissipation of Poynting flux in GRBs. The magnetic field acts as a reservoir of energy and can dissipate its energy to thermal and kinetic energy via the tearing mode instability. We have performed 3D nonlinear MHD simulations of the tearing mode instability in a current sheet. Results from a temporal stability analysis in both the linear regime and weakly nonlinear (Rutherford) regime are compared to the numerical simulations. We observe magnetic island formation, island merging and oscillation once the instability has saturated. The growth in the linear regime is exponential in agreement with linear theory. In the second, Rutherford regime the island width grows linearly with time. We find that thermal energy produced in the current sheet strongly dominates the kinetic energy. Finally preliminary analysis indicates a P(k) 4.8 power law for the power spectral density which suggests that the tearing mode vortices play a role in setting up an energy cascade.

scholarly journals Suppression of neoclassical tearing mode instability at the initial stage by electron cyclotron current drive

AIP Advances ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 035212
Author(s):  
Zhen Yang ◽  
Bin Wu ◽  
Yuanlai Xie ◽  
Yuqing Chen ◽  
Hongming Zhang ◽  
...  
Keyword(s):  
Electron Cyclotron ◽  
Current Drive ◽  
Tearing Mode ◽  
Mode Instability ◽  
Initial Stage ◽  
Neoclassical Tearing Mode

Effect of poloidal equilibrium flow and pressure gradient on the m/n = 2/1 tearing mode

2022 ◽  
Author(s):  
Yue Ming ◽  
Deng Zhou ◽  
Jinfang Wang
Keyword(s):  
Pressure Gradient ◽  
Stability Index ◽  
Plasma Pressure ◽  
Mode Number ◽  
Pressure Perturbation ◽  
Equilibrium Flow ◽  
Tearing Mode ◽  
Mode Instability ◽  
Mode Stability ◽  
Adverse Influence

Abstract The effect of equilibrium poloidal flow and pressure gradient on the m/n = 2/1 (m is the poloidal mode number and n is the toroidal mode number) tearing mode instability for tokamak plasmas is investigated. Based on the condition of ≠0 ( is plasma pressure), the radial part of motion equation is derived and approximately solved for large poloidal mode numbers (m). By solving partial differential equation (Whittaker equation) containing second order singularity, the tearing mode stability index Δ′ is obtained. It is shown that, the effect of equilibrium poloidal flow and pressure gradient has the adverse effect on the tearing mode instability when the pressure gradient is nonzero. The poloidal equilibrium flow with pressure perturbation partially reduces the stability of the classical tearing mode. But the larger pressure gradient in a certain poloidal flow velocity range can abate the adverse influence of equilibrium poloidal flow and pressure gradient. The numerical results do also indicate that the derivative of pressure gradient has a significant influence on the determination of instability region of the poloidal flow with pressure perturbation.

Tearing mode instability in the Bessel function model

1968 ◽  
Vol 10 (12) ◽  
pp. 1101-1104 ◽  
Author(s):  
R D Gibson ◽  
K J Whiteman
Keyword(s):  
Bessel Function ◽  
Tearing Mode ◽  
Mode Instability ◽  
Function Model

scholarly journals Kinetic simulations of the coupling between current instabilities and reconnection in thin current sheets

2000 ◽  
Vol 7 (3/4) ◽  
pp. 141-150 ◽  
Author(s):  
T. Wiegelmann ◽  
J. Büchner
Keyword(s):  
Magnetic Reconnection ◽  
Current Flow ◽  
Flow Direction ◽  
Substantial Contribution ◽  
Tearing Mode ◽  
Tearing Modes ◽  
Tearing Instability ◽  
Instability Modes ◽  
Thin Current Sheet ◽  
Spatial Dimensions

Abstract. We investigate the coupling between current and tearing instability modes of a thin current sheet using the particle code GISMO. We identify pure tearing modes (kx≠ 0), instabilities in the current flow direction (ky≠ 0) and general 3D reconnection modes (kx≠ 0 and ky≠ 0). Our results give evidence that the coupling between tearing modes and current instabilities plays an important role for spontaneous magnetic reconnection. These modes give a substantial contribution to magnetic reconnection, additional to the well known 2D tearing mode. When allowing reconnection to occur in three spatial dimensions, a configuration, which was initially invariant in the current How direction, develops into a configuration with no invariant direction.

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