Resistive toroidal stability of internal kink modes in circular and shaped tokamaks

Journal Article · Wed Jul 01 04:00:00 EDT 1992 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860041· OSTI ID:7285301

Bondeson, A ^[1]; Vlad, G ^[2]; Luetjens, H ^[1]

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1. Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, Ecole Polytechnique Federale de Lausanne, 21 Av. des Bains, CH-1007 Lausanne (Switzerland)
2. Associazione Euratom-ENEA sulla Fusione, C.R.E. Frascati, C.P. 65-00044-Frascati, Rome (Italy)

The linear resistive magnetohydrodynamical stability of the {ital n}=1 internal kink mode in tokamaks is studied numerically. The stabilizing influence of small aspect ratio (Holmes {ital et} {ital al}., Phys. Fluids B {bold 1}, 788 (1989)) is confirmed, but it is found that shaping of the cross section influences the internal kink mode significantly. For finite pressure and small resistivity, curvature effects at the {ital q}=1 surface make the stability sensitively dependent on shape, and ellipticity is destabilizing. Only a very restricted set of finite pressure equilibria is completely stable for {ital q}{sub 0} {lt} 1. A typical result is that the resistive kink mode is slowed down by toroidal effects to a weak resistive tearing/interchange mode. It is suggested that weak resistive instabilities are stabilized during the ramp phase of the sawteeth by effects not included in linear resistive magnetohydrodynamics. Possible mechanisms for triggering a sawtooth crash are discussed.

• OSTI ID: 7285301
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 4:7; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
ASPECT RATIO
CLOSED PLASMA DEVICES
FLUID MECHANICS
HYDRODYNAMICS
INSTABILITY
KINK INSTABILITY
MAGNETOHYDRODYNAMICS
MECHANICS
NUMERICAL SOLUTION
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES