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

Journal Article · Wed Jul 01 00:00:00 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]

---

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), Vol. 4:7; ISSN 0899-8221
• Country of Publication: United States
• Language: English

Related Subjects

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