Experimental investigation of ICRF-edge plasma interactions and surface wave excitation during ICRF heating on EAST

Abstract Although ion cyclotron resonance heating plasma has succeeded in tokamaks, it also faces the problem of wave-related impurities, especially in the future operation environment with an all-metal first wall. By controlling the antenna wave spectrum, we experimentally observed the behavior of impurities and the floating potential on the Experimental Advanced Superconducting Tokamak (EAST) and used the finite element code to calculate the wave propagation at the plasma edge. The results demonstrate that the floating potential is relatively high in the region in the monopole phase is higher than in other phases. Although particular floating potential strength was observed in the low hybrid resonance region, the floating potential was not too high. The simulation results tend to support that under low k // of antenna, the high potential in front of the ion cyclotron range of frequency antenna drives E × B 0 drift, which increases the asymmetry of the poloidal plasma distribution near the antenna and locally enhances the radio frequency sheath and heat load.