Second-order toroidicity-induced Alfven eigenmodes and mode splitting in a low-aspect-ratio tokamak

Journal Article · Thu Oct 01 00:00:00 EDT 1992 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860352· OSTI ID:7008873

Turnbull, A D; Chu, M S; Chance, M S; Greene, J M; Lao, L L; Strait, E J ^[1]

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1. General Atomics, San Diego, California 92186-9784 (United States)

A variational ideal magnetohydrodynamic stability code is used to compute the toroidicity-induced Alfven eigenmode (TAE) for toroidal mode number {ital n}=1 in full toroidal geometry with circular cross section. At finite aspect ratio, toroidicity also couples poloidal mode numbers {ital m} with {ital m}+2 to produce a higher frequency gap in the shear Alfven spectrum, which is associated with a new, second-order TAE mode. It is also found that toroidal coupling between the TAE modes and continuum branches induces splitting of the TAE modes into two or more global modes at slightly different frequencies. Both the new modes and splitting of the TAE modes have important consequences for the identification of TAE modes in experiments.

• DOE Contract Number: AC03-89ER53277; AC02-76CH03073
• OSTI ID: 7008873
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 4:10; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700310 -- Plasma Confinement-- (1992-)
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
ALFVEN WAVES
ANNULAR SPACE
ASPECT RATIO
CLOSED CONFIGURATIONS
CLOSED PLASMA DEVICES
CONFIGURATION
FLUID MECHANICS
HYDRODYNAMICS
HYDROMAGNETIC WAVES
MAGNETIC FIELD CONFIGURATIONS
MAGNETOHYDRODYNAMICS
MECHANICS
SPACE
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TOROIDAL CONFIGURATION
VARIATIONAL METHODS