Giant Oscillations of Electron Temperature during Steady-State Operation on Tore Supra

During fully noninductively driven discharges in the Tore Supra tokamak, large spontaneous oscillations of the core electron temperature (DeltaTe/Te>50%) have been observed for the first time. They occurred during the standard O regime, which is itself characterized by periodic oscillations of much smaller amplitude. The "giant" oscillations appear to involve distinct mechanisms with respect to the O regime and provide a spectacular example of the complex nonlinear interactions between energy confinement, noninductive current sources, and MHD that may occur in a tokamak plasma during steady-state operation.