Upgrade and Experimental Studies of EAST Glow Discharge Cleaning Electrode

The electrode of Glow Discharge Cleaning(GDC) in EAST tokamak was upgraded to an active water-cooling plate anode. Both numerical simulation and experimental studies have confirmed that the new electrode can meet the requirement of heat dissipation with an increased glow current from 3 A to 6 A. Experimental results in EAST show that the breakdown pressure using the new electrode is slightly lower than that using a normal electrode at 1000 V voltage. It is also found that the deuterium removal rate of helium GDC is increased from 1.04×10²³ atoms/h with a normal glow current of 12 A(3 A×4 electrodes), to 2.46×10²³ atoms/h with doubled glow current of 24 A, i.e.,2.4 times higher than before. The results in this paper show that the newly upgraded glow electrode can operate stably at a 6 A current, which greatly improves the deuterium removal rate. It provides an efficient wall conditioning method for future EAST experiments.