' Low frequency Alfvén waves induced by toroidal flows'

Autor: J. P. Goedbloed, B. van der Holst, A. J. C. Beliën
Přispěvatelé: Biophysics Photosynthesis/Energy
Jazyk: angličtina
Rok vydání: 2000
Předmět:
Zdroj: van der Holst, B, Beliën, A J C & Goedbloed, J P 2000, ' " Low frequency Alfvén waves induced by toroidal flows". ', Physics of Plasmas, vol. 7, pp. 4208-4222 . https://doi.org/10.1063/1.1308084
Physics of Plasmas, 7, 4208-4222. American Institute of Physics Publising LLC
ISSN: 1070-664X
DOI: 10.1063/1.1308084
Popis: The magnetohydrodynamic (MHD) spectra of toroidally rotating, axisymmetric tokamaks are analyzed. The continuous spectrum equations for the coupled localized Alfven and slow modes are derived. The effect of flow on this spectrum is threefold: Doppler shift, centrifugal, and Coriolis effects enter. By exploiting a low-β, large aspect ratio expansion, the newly found low frequency Δm=0 Alfven gap [van der Holst et al., Phys. Rev. Lett. 84, 2865 (2000)] located on the rational mode surfaces is analyzed. This gap is created by the geodesic curvature of the field lines, together with finite pressure, and by centrifugal and Coriolis effects. It is determined by a three mode interaction involving a central Alfven mode and two sideband slow modes. From the same scheme, another new purely flow-induced gap inside the Δm=0 gap is found. Also, toroidal flow-induced Alfven eigenmodes (TFAE) are found in the Δm=0 gap. All of these waves may be useful for MHD spectroscopy. Since the gap structures as well as the global ...
Databáze: OpenAIRE