Design of Control System for Suppression of Neoclassical Tearing Modes with Electron Cyclotron Heating and Current Drive on EAST

This paper discusses a control system for the Experimental Advanced Superconducting Tokamak (EAST) that suppresses neoclassical tearing modes (NTMs) (3/2 and 2/1) by applying electron cyclotron (EC) heating and current drive. It allows the magnetic island to be detected and localized in real time and the EC beam to be deposited exactly on the island position by stepwise tuning of the steerable launch mirror. The mode features are identified with temperature perturbation to develop the algorithm for real-time island location. The necessary parameters for the design of the control system are discussed and determined based on simulation of the nonlinear island growth of NTMs with application of EC current drive. Although similar work has been done on many other devices, this is the first attempt on EAST.