Discrete compressional Alfvén eigenmode spectrum in tokamaks
نویسندگان
چکیده
منابع مشابه
Continuous spectrum of shear Alfvén waves within magnetic islands.
The radial structure of the shear Alfvén wave continuous spectrum is calculated inside the separatrix of a magnetic island. We find that, within a magnetic island, there is a continuous spectrum very similar to that of tokamak plasmas, where a generalized safety factor q can be defined and a wide frequency gap is formed, analogous to the ellipticity induced Alfvén eigenmode gap in tokamaks. Thi...
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Neutral-beam injection into plasmas with negative central shear produces a rich spectrum of toroidicity-induced and reversed-shear Alfvén eigenmodes in the DIII-D tokamak. The first application of fast-ion D_{alpha} (FIDA) spectroscopy to Alfvén-eigenmode physics shows that the central fast-ion profile is anomalously flat in the inner half of the discharge. Neutron and equilibrium measurements ...
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Nonlinear saturation of a beta-induced Alfvén eigenmode, driven by slowing down energetic particles via transit resonance, is investigated by the nonlinear hybrid magnetohyrodynamic gyrokinetic code. Saturation is characterized by frequency chirping and symmetry breaking between co- and counter-passing particles, which can be understood as the evidence of resonance detuning. The scaling of the ...
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متن کاملShear Alfvén wave continuous spectrum within magnetic islands
The radial structure of the continuous spectrum of shear Alfvén waves is calculated in this paper within the separatrix of a magnetic island. Geometrical effects due to the noncircularity of the flux surface’s cross section are retained to all orders. On the other hand, only curvature effects responsible for the beta-induced gap in the low-frequency part of the continuous spectrum are kept. Mod...
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ژورنال
عنوان ژورنال: Nuclear Fusion
سال: 2006
ISSN: 0029-5515,1741-4326
DOI: 10.1088/0029-5515/46/10/s10