EFDA–JET–CP(14)06/02

Core Microturbulence and Edge MHD Interplay and Stabilization by Fast Ions in Tokamak Confined Plasmas

ABSTRACT. Extensive linear and non-linear gyrokinetic simulations and linear MHD analyses performed for two JET hybrid discharges have shown that the large population of fast ions found in the plasma core under particular heating conditions has a strong impact on core microturbulence and edge MHD by reducing core ion heat fluxes and increasing pedestal pressure in a feedback mechanism. This mechanism is found to be highly dependent on plasma triangularity as it changes the balance between the improvement in the plasma core and the edge. The feedback mechanism plays a similar role in the ITER hybrid scenario as in the JET discharges analyzed due to its high triangularity plasmas and the large amount of fast ions generated in the core by the heating systems and the alpha power.
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EFDC140602 1.13 Mb