Development of magnetohydrodynamic modes during sawteeth in tokamak plasmas
- Laboratoire de Physique des Plasmas, CNRS-Ecole Polytechnique, 91128 Palaiseau cedex (France)
- Centro Atómico Bariloche (CNEA) and Instituto Balseiro (UNC-CNEA), San Carlos de Bariloche, RN 8400 (Argentina)
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bariloche (Argentina)
- Laboratoire d'Optique Appliquée, ENSTA, CNRS, Ecole Polytechnique, 91761 Palaiseau (France)
A dynamical analysis applied to a reduced resistive magnetohydrodynamics model is shown to explain the chronology of the nonlinear destabilization of modes observed in tokamak sawteeth. A special emphasis is put on the nonlinear self-consistent perturbation of the axisymmetric m = n = 0 mode that manifests through the q-profile evolution. For the very low fusion-relevant resistivity values, the q-profile is shown to remain almost unchanged on the early nonlinear timescale within the central tokamak region, which supports a partial reconnection scenario. Within the resistive region, indications for a local flattening or even a local reversed-shear of the q-profile are given. The impact of this ingredient in the occurrence of the sawtooth crash is discussed.
- OSTI ID:
- 22227942
- Journal Information:
- Physics of Plasmas, Vol. 20, Issue 7; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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