Progress in hydrogen control research in high power long pulse plasma mode

[ Instrument Network Instrument Development ] Hydrogen and fuel recycling is one of the important scientific issues in the operation of Tokamak high-power long-pulse plasma. Recently, the research results of the researcher Yu Yaowei of the Vacuum and Wall Treatment Group of the Institute of Plasma were published in the Nuclear Fusion Journal, the top nuclear fusion journal.

Recirculation Control of EAST Long Pulse H-Mode Plasma

This work compares and analyzes the effects of conventional wall treatment methods, lithiated silicified coating treatment, built-in cryopump and lithium bomb injection on the recycling of EAST multi-round physical experiment data. The results show that the built-in cryopump particle discharge rate can reach 1020-1021 D-atoms/s and the recycling coefficient Rglobal is reduced from 1.0 to 0.8, which can effectively reduce the neutral pressure and fuel recycling in the divertor target plate area. effect. The effect of coating treatment on the control of hydroquinone ratio is obviously better than that of conventional methods such as first wall baking and discharge cleaning. In particular, the lithiated coating can reduce the hydroquinone ratio to 3%, and the work also applies to the lithium shot injection technology. The control problem of recycling was analyzed. The combination of various wall treatment methods can reduce the hydroquinone ratio and the recycle coefficient, providing good significant wall conditions for the 101 second H mode plasma acquisition. Related Results This will provide reference experience for future EAST and other fusion devices operating at higher power 400-1000 second long pulse steady-state H-mode plasmas.

The research was strongly supported by the EAST team and was funded by projects such as the National Natural Science Foundation and the National Key R&D Program.

Figure 2. Effect of plasma position control on recirculation