Detachment plasma achieved based on active temperature feedback system in EAST

Abstract

The infrared (IR) thermography diagnostic has recently been upgraded to achieve real-time temperature measurement and feedback capability in the experimental advanced superconducting tokamak (EAST). A new control and data acquisition program for IR camera is developed with online temperature calibration and compensation. Reflective memory (RFM) is configured in the data acquisition system for real-time data transmission to the plasma control system (PCS). Based on the upgraded IR thermography diagnostic, detachment plasma has been achieved for the first time in EAST with active temperature feedback. The divertor impurity seeding system is used to inject a sequence of short neon impurity pulses with 50% D2 to increase the edge radiation of the plasma particles. The temperature of the divertor target plates decreases to the preset target value and the divertor detachment has been realized with no serious reduction of plasma stored energy and confinement observed in the temperature feedback control phase. As a new feedback control method, the IR temperature feedback control shows great application prospects for the temperature and heat flux control of the first wall components in future long pulse operation of EAST.