TY - JOUR

T1 - On the influence of the local maxima of total pressure on the current sheet stability to the kink-like (flapping) mode

AU - Korovinskiy, D. B.

AU - Erkaev, N. V.

AU - Semenov, V. S.

AU - Ivanov, I. B.

AU - Kiehas, S. A.

AU - Ryzhkov, I. I.

PY - 2018/2

Y1 - 2018/2

N2 - The stability of the Fadeev-like current sheet with respect to transversally propagating kink-like perturbations (flapping mode) is considered in terms of two-dimensional linear magnetohydrodynamic numerical simulations. It is found that the current sheet is stable when the total pressure minimum is located in the sheet center and unstable when the maximum value is reached there. It is shown that an unstable spot of any size enforces the whole sheet to be unstable, though the increment of instability decreases with the reduction of the unstable domain. In unstable sheets, the dispersion curve of instability shows a good match with the double-gradient (DG) model prediction. Here, the typical growth rate (short-wavelength limit) is close to the DG estimate averaged over the unstable region. In stable configurations, the typical frequency matches the maximum DG estimate. The dispersion curve of oscillations demonstrates a local maximum at wavelength similar to 0.7 sheet half-width, which is a new feature that is absent in simplified analytical solutions. (C) 2018 Author(s).

AB - The stability of the Fadeev-like current sheet with respect to transversally propagating kink-like perturbations (flapping mode) is considered in terms of two-dimensional linear magnetohydrodynamic numerical simulations. It is found that the current sheet is stable when the total pressure minimum is located in the sheet center and unstable when the maximum value is reached there. It is shown that an unstable spot of any size enforces the whole sheet to be unstable, though the increment of instability decreases with the reduction of the unstable domain. In unstable sheets, the dispersion curve of instability shows a good match with the double-gradient (DG) model prediction. Here, the typical growth rate (short-wavelength limit) is close to the DG estimate averaged over the unstable region. In stable configurations, the typical frequency matches the maximum DG estimate. The dispersion curve of oscillations demonstrates a local maximum at wavelength similar to 0.7 sheet half-width, which is a new feature that is absent in simplified analytical solutions. (C) 2018 Author(s).

KW - MAGNETIC-FIELD

KW - PLASMA SHEET

KW - SHEAR-FLOW

KW - MAGNETOTAIL

KW - CLUSTER

KW - CONFIGURATIONS

KW - OSCILLATIONS

KW - INSTABILITY

KW - EQUILIBRIA

UR - http://www.scopus.com/inward/record.url?scp=85042064428&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/influence-local-maxima-total-pressure-current-sheet-stability-kinklike-flapping-mode

U2 - 10.1063/1.5016934

DO - 10.1063/1.5016934

M3 - статья

VL - 25

JO - Physics of Plasmas

JF - Physics of Plasmas

SN - 1070-664X

IS - 2

M1 - 022904

ER -