The effect of plasma flow on line-tied magnetohydrodynamic modes

Journal Article · Tue Jun 15 00:00:00 EDT 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3418317· OSTI ID:21378015

Arcudi, Francesco ^[1]; Delzanno, Gian Luca; Finn, John M ^[2]

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1. Dipartimento di Energetica, Politecnico di Torino, 10129 Torino (Italy)
2. T-5, Applied Mathematics and Plasma Physics Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

The linear stability of a linear pinch to kink modes with line-tying boundary conditions and equilibrium axial flow is studied. Numerical results in visco-resistive magnetohydrodynamics show that for long plasmas, in which the line-tying stabilization effect is weak, plasma flow is stabilizing. For shorter plasmas, near the length at which line-tying stabilizes the mode for zero flow, the flow can be destabilizing. A simple model using reduced ideal magnetohydrodynamics with a step-function current density and an even simpler one-dimensional sound wave model with equilibrium flow elucidate these effects. It is concluded that: (1) The stabilization in long plasmas is due to convective stabilization; (2) the destabilization for short plasmas can be explained using a picture involving the coupling of two stable waves, one propagating in the forward direction and one in the backward direction; and (3) strong magnetic shear suppresses the flow destabilization for short plasmas.

• OSTI ID: 21378015
• Journal Information: Physics of Plasmas, Vol. 17, Issue 6; Other Information: DOI: 10.1063/1.3418317; (c) 2010 American Institute of Physics; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BOUNDARY CONDITIONS
COUPLING
CURRENT DENSITY
EQUILIBRIUM
HYDROMAGNETIC WAVES
ION ACOUSTIC WAVES
KINK INSTABILITY
MAGNETOHYDRODYNAMICS
PLASMA
SOUND WAVES
STABILIZATION
FLUID MECHANICS
HYDRODYNAMICS
INSTABILITY
ION WAVES
MECHANICS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMA WAVES