Design and implementation of power and phase feedback control system for ICRH on EAST

Ion cyclotron wave resonance heating(ICRH)is one of the most important auxiliary methods to heat plasma in the Experimental Advanced Superconducting Tokamak(EAST).Several megawatts of power is transmitted through separate coaxial lines and coupled with the plasma through arrays of loop antennas.The parameters of the ICRH system,including the injected power and phasing between antenna straps,are critical to the coupling efficiency of the power as well as the resulting impact on the heating efficiency.In this paper,we present a system for feedback control of the phase between the current straps and the ICRH power on EAST.The feedback control system was tested using both a matched dummy load and a plasma load,and it successfully maintained stable operationin the2016EAST campaign.Good control of the injected power and wave phases was achieved during edgelocalized mode operation.