Investigation on Hydrogen Removal Efficiency of Helium Taylor Discharge Cleaning on J-TEXT Tokamak

The hydrogen absorbed on the first wall of the tokamak device will desorbed during the experiment. This additional hydrogen makes plasma density increase so that the plasma density cannot be controlled at experimental setting value. In this paper, in order to remove the adsorbed hydrogen on the first wall of the vacuum chamber as much as possible before the formal experiment, we measured the desorption rate of hydrogen in helium Taylor discharge cleaning and helium Taylor discharge cleaning with baking. Experimental results show that the use of helium Taylor discharge cleaning on J-TEXT can effectively remove hydrogen in the main vacuum chamber. The next experiments of adjusting the discharge cleaning parameters were carried out to measure the desorption rate change of hydrogen. And the best Taylor discharge cleaning parameters were determined according to the highest hydrogen desorption rate.