Magnetohydrodynamic instability excited by interplay between a resistive wall mode and stable ideal magnetohydrodynamic modes in rotating tokamak plasmas

In a rotating toroidal plasma surrounded by a resistive wall, it is shown that linear magnetohydrodynamic (MHD) instabilities can be excited by interplay between the resistive wall mode (RWM) and stable ideal MHD modes, where the RWM can couple with not only a stable external kink mode but also vari...

Full description

Saved in:
Bibliographic Details
Published in:Physics of plasmas 2015-08, Vol.22 (8)
Main Authors: Aiba, N., Hirota, M.
Format: Article
Language:English
Subjects:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALFVEN WAVES
DISPERSION RELATIONS
DOPPLER EFFECT
EIGENFREQUENCY
FIRST WALL
INSTABILITY
LANDAU DAMPING
MAGNETOHYDRODYNAMICS
PLASMA
ROTATING PLASMA
TOKAMAK DEVICES
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In a rotating toroidal plasma surrounded by a resistive wall, it is shown that linear magnetohydrodynamic (MHD) instabilities can be excited by interplay between the resistive wall mode (RWM) and stable ideal MHD modes, where the RWM can couple with not only a stable external kink mode but also various stable Alfvén eigenmodes that abound in a toroidal plasma. The RWM growth rate is shown to peak repeatedly as the rotation frequency reaches specific values for which the frequencies of the ideal MHD modes are Doppler-shifted to the small RWM frequency. Such destabilization can be observed even when the RWM in a static plasma is stable. A dispersion relation clarifies that the unstable mode changes from the RWM to the ideal MHD mode destabilized by wall resistivity when the rotation frequency passes through these specific values. The unstable mode is excited at these rotation frequencies even though plasma rotation also tends to stabilize the RWM from the combination of the continuum damping and the ion Landau damping.
ISSN:1070-664X
1089-7674
DOI:10.1063/1.4928892