scholarly journals Formation and Reconnection of Three-dimensional Current Sheets with a Guide Field in the Solar Corona

2017 ◽  
Vol 849 (1) ◽  
pp. 28 ◽  
Author(s):  
J. K. Edmondson ◽  
B. J. Lynch
Keyword(s):  
Solar Corona ◽  
Three Dimensional ◽  
Current Sheets ◽  
Guide Field

scholarly journals Distinctive features of the structure of current sheets formed in plasma in three-dimensional magnetic configurations with an X line (a review)

2021 ◽  
Vol 9 (6) ◽  
pp. 464-478
Author(s):  
Anna Frank
Keyword(s):  
Longitudinal Magnetic Field ◽  
Initial Conditions ◽  
Three Dimensional ◽  
Limited Range ◽  
Transverse Plane ◽  
Plasma Current ◽  
Initial Value ◽  
Distinctive Features ◽  
Current Sheets ◽  
Guide Field

A review is presented on experimental results related to investigation of distinctive features of the structure and evolution of plasma current sheets formed in three dimensional (3D) magnetic configurations with an X line, in the presence of a longitudinal magnetic field component (guide field) directed along the X line. It is shown that formation of a plasma current sheet results in enhancement of the guide field within the sheet. The excessive guide field is maintained by plasma currents that flow in the transverse plane relative to the main current in the sheet. As a result, the structure of the currents becomes three-dimensional. Increasing the initial value of the guide field brings about a decrease of compression into the sheet of both the electric current and plasma. This effect is caused by changing the pres- sure balance in the sheet when an excessive guide field appears in it. Deformation of plasma current sheets in 3D magnetic configurations, namely, an appearance of asymmetric and tilted sheets, results from excitation of the Hall currents and their interaction with the guide field. It is shown that the formation of current sheets in 3D magnetic configurations with an X line is possible in a relatively wide, but limited range of initial conditions

scholarly journals Effect of guide field on three-dimensional electron shear flow instabilities in electron current sheets

2015 ◽  
Vol 81 (6) ◽  
Author(s):  
Neeraj Jain ◽  
Jörg Büchner
Keyword(s):  
Shear Flow ◽  
Current Sheet ◽  
Three Dimensional ◽  
Sheet Thickness ◽  
Electron Current ◽  
Tearing Mode ◽  
Current Sheets ◽  
Tearing Modes ◽  
Guide Field ◽  
Half Thickness

We examine, in the limit of electron plasma ${\it\beta}_{e}\ll 1$, the effect of an external guide field and current sheet thickness on the growth rates and nature of three-dimensional (3-D) unstable modes of an electron current sheet driven by electron shear flow. The growth rate of the fastest growing mode drops rapidly with current sheet thickness but increases slowly with the strength of the guide field. The fastest growing mode is tearing type only for thin current sheets (half-thickness ${\approx}d_{e}$, where $d_{e}=c/{\it\omega}_{pe}$ is the electron inertial length) and zero guide field. For finite guide field or thicker current sheets, the fastest growing mode is a non-tearing type. However, growth rates of the fastest 2-D tearing and 3-D non-tearing modes are comparable for thin current sheets ($d_{e}<\text{half thickness}<2\,d_{e}$) and small guide field (of the order of the asymptotic value of the component of magnetic field supporting the electron current sheet). It is shown that the general mode resonance conditions for tearing modes depend on the effective dissipation mechanism. The usual tearing mode resonance condition ($\boldsymbol{k}\boldsymbol{\cdot }\boldsymbol{B}_{0}=0$, $\boldsymbol{k}$ is the wavevector and $\boldsymbol{B}_{0}$ is the equilibrium magnetic field) can be recovered from the general resonance conditions in the limit of weak dissipation. The conditions (relating current sheet thickness, strength of the guide field and wavenumbers) for the non-existence of tearing mode are obtained from the general mode resonance conditions. We discuss the role of electron shear flow instabilities in magnetic reconnection.

scholarly journals FORMATION AND RECONNECTION OF THREE-DIMENSIONAL CURRENT SHEETS IN THE SOLAR CORONA

2010 ◽  
Vol 718 (1) ◽  
pp. 72-85 ◽  
Author(s):  
J. K. Edmondson ◽  
S. K. Antiochos ◽  
C. R. DeVore ◽  
T. H. Zurbuchen
Keyword(s):  
Solar Corona ◽  
Three Dimensional ◽  
Current Sheets

Drift instabilities in current sheets with guide field

2008 ◽  
Vol 15 (7) ◽  
pp. 072101 ◽  
Author(s):  
P. H. Yoon ◽  
A. T. Y. Lui
Keyword(s):  
Current Sheets ◽  
Guide Field
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