Radiative Feedback Control on EAST

As a well acknowledged and effffective way to solve the excessive heat load on divertor targets, the active feedback control of radiated power for divertor heat spread is achieved on the EAST. The radiative control algorithm is implemented in the EAST Plasma Control System (PCS). The radiative intensity in plasma discharges is measured by a horizontal absolute extreme ultraviolet (AXUV) array, the data from which is transferred to a specialized server that calculates the total radiated power of the bulk plasma, all in real time. The control system includes two kinds of gas puffiffiffing devices to seed pure neon: the supersonic molecular beam injection (SMBI) at the mid-plane as the feedback actuator, and the piezoelectric (PE) valves located on the divertor targets as the feedforward actuators. The active radiative control system is fast and stable during long pulse discharges, and the radiated power can be effffectively controlled in both L-mode and H-mode.