A general MHD formulation for plasmas with flow and resistive walls

Journal Article · Thu Nov 30 04:00:00 EST 2006 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2404570· OSTI ID:20895143

Guazzotto, L; Freidberg, J P ^[1]; Betti, R ^[2]

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1. Massachusetts Institute of Technology, Cambridge, MA (United States)
2. University of Rochester, Rochester, NY (United States)

Toroidal rotation, either induced by means of neutral beams (e.g. in NSTX and DIII-D) or appearing spontaneously (e.g. in Alcator C-Mod, JET and Tore Supra) is routinely observed in modem tokamak experiments. Poloidal rotation is also commonly observed, in particular in the edge region of the plasma. Plasma rotation has a major effect on plasma stability. Flow and flow shear stabilize external modes such as the resistive wall mode (as observed e.g. in DIII-D), suppress turbulence when the flow shear is large enough, and also have a significant influence on the stability and nonlinear evolution of the internal kink and ballooning modes. Flow shear can in particular have both a stabilizing (by breaking up unstable structures) and destabilizing (through the Kelvin-Helmoltz mechanism) effect. A self-consistent analysis of the effect of rotation requires the use of numerical tools. In this work, we present a general eigenvalue formulation based on a variational principle stability analysis, including arbitrary (both toroidal and poloidal) plasma rotation and a thin resistive wall of arbitrary shape and resistivity. It is shown that the problem can always be reduced to a classic eigenvalue formulation of the kind i{omega}A double underbar {center_dot} {zeta}-vector = B double underbar {center_dot} {zeta}-vector, where {zeta}-vector is the unknown eigenvector related to the plasma displacement, and {omega} the (complex) evolution frequency of the perturbation. The formulation is well suited for a finite element analysis.

• OSTI ID: 20895143
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 871; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALCATOR DEVICE
BALLOONING INSTABILITY
DOUBLET-3 DEVICE
EIGENVALUES
EIGENVECTORS
FINITE ELEMENT METHOD
JET TOKAMAK
KINK INSTABILITY
MAGNETOHYDRODYNAMICS
MATHEMATICAL EVOLUTION
NONLINEAR PROBLEMS
NSTX DEVICE
PLASMA
PLASMA CONFINEMENT
ROTATION
TORE SUPRA TOKAMAK
VARIATIONAL METHODS
WALL EFFECTS