Stability criteria for edge flute modes in the two-fluid regime

Journal Article · Sat May 01 00:00:00 EDT 1993 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860879· OSTI ID:6641483

Zheng, L ^[1]

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1. Max-Planck-Institut fuer Plasmaphysik, IPP-EURATOM Association, D-8046 Garching bei Muenchen (Germany)

Necessary and sufficient stability criteria for flute modes localized at the edge of toroidal plasmas are obtained from the Braginskii's two-fluid equations without taking into account the collisional effects. It is assumed that the plasma pressure tends to vanish, but its gradient remains finite at the edge of the plasma. The results show that the free-boundary edge flute modes (namely, the peeling modes) are more dangerous than the fixed-boundary modes (namely, the Mercier modes). Numerical investigation of the criterion for peeling modes shows that the finite ion-gyroradius effect can substantially stabilize the modes, especially for the case [Delta][ge]0, where the equilibrium quantity [Delta][equivalent to]1/2+[ital S][sup [minus]1][lt][bold j][center dot][bold B][vert bar][del][ital v][vert bar][sup [minus]2][gt], with [ital S] denoting the global shear, [bold B] the magnetic field, [bold j] the current density, [ital v] the volume inside the reference magnetic surface, and [lt]...[gt] denoting the average over the magnetic surface. Equilibria with [Delta][ge]0 are shown to be more stable to the peeling modes than those with [Delta][le]0.

• OSTI ID: 6641483
• Journal Information: Physics of Fluids B; (United States), Vol. 5:5; ISSN 0899-8221
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
FLUTE INSTABILITY
MAGNETIC SURFACES
MERCIER CRITERION
PLASMA CONFINEMENT
PLASMA MACROINSTABILITIES
PLASMA PRESSURE
TOKAMAK DEVICES
TOROIDAL CONFIGURATION
ANNULAR SPACE
CLOSED CONFIGURATIONS
CLOSED PLASMA DEVICES
CONFIGURATION
CONFINEMENT
INSTABILITY
MAGNETIC FIELD CONFIGURATIONS
PLASMA INSTABILITY
SPACE
THERMONUCLEAR DEVICES
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