Electron cyclotron heating (ECH) is used to suppress m = 2 magnetohydrodynamic (MHD) oscillations in the Texas Experimental Tokamak (TEXT) [Nucl. Technol. Fusion 1, 479 ( 1981 )]. The location of ECH power deposition is controlled by a movable antenna. The MHD activity is suppressed when the ECH beam is directed close to the q=2 surface. The experiment is simulated using a three-dimensional resistive MHD code in cylindrical geometry. For fixed plasma current, the saturated m = 2 island width is found to depend on the value of the safety factor at the magnetic axis (q0). The simulation suggests that the observed saturated m=2 island in the pre-ECH plasma, which typically occupies 25% of the minor radius, corresponds to q0∼ 1.3. The suppression of the island in the presence of ECH is attributed to current profile modification. In some discharges, the m = 2 activity does not resume even after the ECH pulse is turned off.
All Science Journal Classification (ASJC) codes
- Computational Mechanics
- Condensed Matter Physics
- Mechanics of Materials
- Physics and Astronomy(all)
- Fluid Flow and Transfer Processes