Theory of continuum damping of toroidal Alfven eigenmodes in finite-[beta] tokamaks

Journal Article · Fri Oct 01 00:00:00 EDT 1993 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860839· OSTI ID:6022147

Zonca, F; Chen, L ^[1]

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1. Plasma Physics Laboratory and Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08543 (United States)

A general theoretical approach has been formulated for analyzing two-dimensional structures of high-[ital n] toroidal Alfven eigenmodes (TAE) in large aspect-ratio, finite-[beta] tokamaks. Here, [ital n] is the toroidal wave number and [beta] is the ratio between plasma and magnetic pressures. The present approach generalizes the standard ballooning-mode formalism and is capable of treating eigenmodes with extended global radial structures, as well as finite coupling between discrete and continuous spectra. Employing the well-known ([ital s],[alpha]) model equilibrium and assuming a linear equilibrium profile, the present approach has been applied to the calculation of the resonant continuum damping rate of TAE modes. Here, [ital s] and [alpha] denote, respectively, the strengths of magnetic shear and pressure gradients. In particular, it is found that there exists a critical [alpha] value, [alpha][sub [ital c]]([ital s]), such that, as [alpha][r arrow][alpha][sub [ital c]], the continuum damping rate is significantly enhanced and, thus, could suppress the potential TAE instability.

• OSTI ID: 6022147
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 5:10; ISSN 0899-8221; ISSN PFBPEI
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
ALFVEN WAVES
ALPHA PARTICLES
BALLOONING INSTABILITY
CHARGED PARTICLES
CLOSED PLASMA DEVICES
CONFINEMENT
DAMPING
EIGENSTATES
FLUID MECHANICS
HYDRODYNAMICS
HYDROMAGNETIC WAVES
INSTABILITY
MAGNETOHYDRODYNAMICS
MECHANICS
PLASMA CONFINEMENT
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES