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Title: Thermal instability of a reconnecting current layer as a trigger for solar flares

Abstract

The stability of small perturbations of a reconnecting current layer (CL) in a plasma with a strong magnetic field has been investigated in the approximation of dissipative magnetohydrodynamics. The case where the wavevector of the perturbations is parallel to the electric current in the CL has been considered. The suppression of plasma heat conduction by a magnetic field perturbation inside the CL is shown to be responsible for the instability. At the linear stage of instability development, the perturbations grow with the characteristic radiative plasma cooling time calculated in the approximation of an optically thin plasma with cosmic abundances of elements. The formation of a periodic structure of cold and hot magnetic flux tubes, viz., filaments, located across the direction of the electric current, should be expected at the nonlinear stage of the instability in the CL. The proposed mechanism of the thermal CL instability can explain the sequential brightening (ignition) in the arcades of magnetic loops in solar flares.

Authors:
;  [1]
  1. Moscow State University, Sternberg Astronomical Institute (Russian Federation)
Publication Date:
OSTI Identifier:
22756357
Resource Type:
Journal Article
Journal Name:
Journal of Experimental and Theoretical Physics
Additional Journal Information:
Journal Volume: 125; Journal Issue: 2; Other Information: Copyright (c) 2017 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1063-7761
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DISTURBANCES; ELECTRIC CURRENTS; INSTABILITY; LAYERS; MAGNETIC FIELDS; MAGNETIC FLUX; MATRICES; NONLINEAR PROBLEMS; OPTICALLY THIN PLASMA; PERTURBATION THEORY; SOLAR FLARES; THERMAL CONDUCTION

Citation Formats

Ledentsov, L. S., E-mail: koob@mail.ru, and Somov, B. V., E-mail: somov.boris@gmail.com. Thermal instability of a reconnecting current layer as a trigger for solar flares. United States: N. p., 2017. Web. doi:10.1134/S1063776117070214.
Ledentsov, L. S., E-mail: koob@mail.ru, & Somov, B. V., E-mail: somov.boris@gmail.com. Thermal instability of a reconnecting current layer as a trigger for solar flares. United States. doi:10.1134/S1063776117070214.
Ledentsov, L. S., E-mail: koob@mail.ru, and Somov, B. V., E-mail: somov.boris@gmail.com. Tue . "Thermal instability of a reconnecting current layer as a trigger for solar flares". United States. doi:10.1134/S1063776117070214.
@article{osti_22756357,
title = {Thermal instability of a reconnecting current layer as a trigger for solar flares},
author = {Ledentsov, L. S., E-mail: koob@mail.ru and Somov, B. V., E-mail: somov.boris@gmail.com},
abstractNote = {The stability of small perturbations of a reconnecting current layer (CL) in a plasma with a strong magnetic field has been investigated in the approximation of dissipative magnetohydrodynamics. The case where the wavevector of the perturbations is parallel to the electric current in the CL has been considered. The suppression of plasma heat conduction by a magnetic field perturbation inside the CL is shown to be responsible for the instability. At the linear stage of instability development, the perturbations grow with the characteristic radiative plasma cooling time calculated in the approximation of an optically thin plasma with cosmic abundances of elements. The formation of a periodic structure of cold and hot magnetic flux tubes, viz., filaments, located across the direction of the electric current, should be expected at the nonlinear stage of the instability in the CL. The proposed mechanism of the thermal CL instability can explain the sequential brightening (ignition) in the arcades of magnetic loops in solar flares.},
doi = {10.1134/S1063776117070214},
journal = {Journal of Experimental and Theoretical Physics},
issn = {1063-7761},
number = 2,
volume = 125,
place = {United States},
year = {2017},
month = {8}
}