Diamagnetic thresholds for sawtooth cycling in tokamak plasmas
Abstract
The cycling dynamics of the internal kink mode, which drives sawtooth oscillations in tokamak plasmas, is studied using the three dimensional, non-linear magnetohydrodynamic (MHD) code XTOR-2F [H. Lütjens and J.-F. Luciani, J. Comput. Phys. 229, 8130 (2010)]. It is found that sawtooth cycling, which is characterized by quiescent ramps and fast crashes in the experiment, can be recovered in two-fluid MHD provided that a criterion of diamagnetic stabilization is fulfilled. The simulation results indicate that diamagnetic effects alone may be sufficient to drive sawteeth with complete magnetic reconnection in high temperature Ohmic plasmas.
- Publication:
-
Physics of Plasmas
- Pub Date:
- October 2011
- DOI:
- Bibcode:
- 2011PhPl...18j2501H
- Keywords:
-
- kink instability;
- magnetic reconnection;
- plasma magnetohydrodynamics;
- plasma oscillations;
- plasma simulation;
- plasma temperature;
- plasma toroidal confinement;
- sawtooth instability;
- Tokamak devices;
- 52.55.Fa;
- 52.35.Fp;
- 52.65.-y;
- 52.35.Vd;
- 52.30.Cv;
- 52.35.Py;
- Tokamaks spherical tokamaks;
- Electrostatic waves and oscillations;
- Plasma simulation;
- Magnetic reconnection;
- Magnetohydrodynamics;
- Macroinstabilities