Geodesic acoustic modes in toroidally rotating tokamaks with an arbitrary β

Journal Article · Mon Jul 15 04:00:00 EDT 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4816672· OSTI ID:22227949

Ren, Haijun ^[1]; Li, Ding ^[1]; Chu, Paul K ^[2]

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1. CAS Key Laboratory of Geospace Environment and Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China)
2. Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong)

Theoretical research on the geodesic acoustic mode (GAM) induced by the equilibrium toroidal rotation flow (ETRF) in the tokamak plasmas with an arbitrary β is performed by using the ideal magnetohydrodynamic model, where β is the ratio of the plasma pressure and magnetic field pressure. Two equations determining the poloidal displacement ξ{sub θ} and the divergence of the Lagrangian perturbation are obtained and suitable for arbitrary cross-section tokamaks with large-aspect-ratios. The dispersion relations are then derived for two different coupling patterns by assuming ξ{sub ±2}=0 and ξ{sub ±4}=0, respectively, where ξ{sub m}=(1/2π)∫ξ{sub θ}e{sup imθ}dθ with θ being the poloidal angle under the circular cross-section condition. In both patterns, the ETRF will increase the frequencies of the GAMs but β can decrease them. The GAM for ξ{sub ±2}=0 has a larger frequency than GAM for ξ{sub ±4}=0.

• OSTI ID: 22227949
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 7 Vol. 20; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ASPECT RATIO
BETA RATIO
DIFFERENTIAL GEOMETRY
DISPERSION RELATIONS
DISTURBANCES
GEODESICS
LAGRANGIAN FUNCTION
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
PLASMA CONFINEMENT
PLASMA PRESSURE
TOKAMAK DEVICES