Integrated plasma control for long pulse advanced plasma discharges on EAST

Abstract

For long pulse or steady-state advanced plasma discharges, it is necessary to keep plasma parameters such as plasma shape, loop voltage, plasma pressure in a steady state way. In particular, the heat load on the divertor target must be effectively reduced. By using Low Hybrid Wave (LHW) for the current drive, loop voltage has been feedback controlled while plasma current was controlled by the PF coil current. The control of the plasma pressure has been demonstrated by using LHW. Heat load reduction has been done by radiation and advanced shape configuration. By using impurity seeding with gas puff for the feedforward and Super-Sonic Molecular Beam Injection (SMBI) to feedback the total radiation, radiation can be effectively controlled with slight influence to the core confinement. The quasi-snowflake (QSF) discharge in H-mode has been achieved. It is verified again in H-mode operation, heat load can be effectively reduced under the QSF shape. All these new control algorithms give rise to more assistances to the EAST long pulse operation.