Magnetohydrodynamic counter-rotating vortices and synergetic stabilizing effects of magnetic field and plasma flow
- Association Euratom-Hellenic Republic, Division of Theoretical Physics, University of Ioannina, GR 451 10 Ioannina (Greece)
- Max-Planck-Institut fuer Plasmaphysik, Euratom Association, D-85748 Garching (Germany)
A nonlinear two-dimensional steady state solution in the framework of hydrodynamics describing a row of periodic counter-rotating vortices is extended to the magnetohydrodynamic (MHD) equilibrium equation with incompressible flow of arbitrary direction. The extended solution covers a variety of equilibria because four surface quantities remain free. Similar to the case of the MHD cat-eyes equilibrium [Throumoulopoulos et al., J. Phys. A: Math. Theor. 42, 335501 (2009)] and unlike linear equilibria, the flow has a strong impact on isobaric surfaces by forming pressure islands located within the counter-rotating vortices even for values of beta (defined as the ratio of the thermal pressure over the external axial magnetic-field pressure) on the order of 0.01. Also, the axial current density is appreciably modified by the flow. Furthermore, a magnetic-field-aligned flow of experimental fusion relevance, i.e., for Alfven Mach numbers of the order of 0.01, and the flow shear in combination with the variation of the magnetic field perpendicular to the magnetic surfaces have significant stabilizing effects potentially related to the equilibrium nonlinearity. The stable region is enhanced by an external axial magnetic field.
- OSTI ID:
- 21347187
- Journal Information:
- Physics of Plasmas, Vol. 17, Issue 3; Other Information: DOI: 10.1063/1.3353077; (c) 2010 American Institute of Physics; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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