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2004
An investigation is presented of the effect of an error field on the growth of a resistive wall mode (RWM). This issue is of importance to many toroidal confinement devices, but particularly to the proposed International Thermonuclear Experimental Reactor (ITER) [ITER Physics Basis, Nucl. Fusion 39 , 2175 (1999)], where if advanced tokamak performa…
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2003
The linear stability of high-toroidal-number drift-ballooning modes in tokamaks is investigated with a model that includes resistive and viscous dissipation, and assumes the mode frequency to be comparable to both the sound and diamagnetic frequencies. The coupled effect of ion drift waves and electron drift-acoustic waves is shown to be important,…
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2001
The resistive wall mode ~ RWM ! poses a threat to many plasma confinement devices. The continuous rotation of the wall relative to the plasma makes it appear perfectly conducting, because of the skin effect, but this is ineffective if the perturbation locks to the wall. This raises the question of whether a nonuniformly rotating wall is more effect…
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2001
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2000
The finite resistivity of the wall that surrounds any toroidal plasma confinement device can lead to a branch of instabilities known as the resistive wall mode (RWM). Theory indicates that the RWM is potentially activated whenever the plasma equilibrium is unstable with the wall placed at infinity. In particular, advanced tokamak power plant design…
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2000
A model is developed to analyze the stabilization of the resistive wall mode (RWM) by plasma rotation. Central to the model is a cylindrical plasma that is ideal magnetohydrodynamic unstable in the absence of a wall, and possesses an internal resonance [J. M. Finn, Phys. Plasmas 2 , 198 (1995)]. This system is then a qualitative model for the actua…
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1999
The possibility of stabilizing ideal magnetohydrodynamical (MHD) instabilities by resistive walls and slow plasma rotation (rotation frequencies comparable to resistive tearing growth rates) was proposed recently by Finn [Phys. Plasmas 2 , 3782 (1995)] on the basis of cylindrical theory. In the present paper we analyze toroidal effects (pressure gr…
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1999
It has been suggested [Kleva and Guzdar, Phys. Plasmas 6 , 116 (1999)] that reconnecting ballooning modes in which electron inertia replaces resistivity in a nonideal magnetohydrodynamic Ohm’s law can have substantial growth rates in the low collisionality regime. Numerical calculation, albeit necessarily at unrealistically large values of the co…
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1998
A new formalism for analyzing the magnetohydrodynamic stability of a limiter tokamak edge plasma is developed. Two radially localized, high toroidal mode number n instabilities are studied in detail: a peeling mode and an edge ballooning mode. The peeling mode, driven by edge current density and stabilized by edge pressure gradient, has features wh…
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1997
The bootstrap current in a non-Maxwellian tokamak plasma with electron cyclotron heating is calculated. The calculation is exact in the limit of highly charged ions, where pitch-angle scattering dominates over quasilinear diffusion, and shows that the current is entirely determined by the pressure of the trapped electrons. If the ion charge is fini…
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