New discovery get, when Pellet fueling first time used in ELM suppression with RMPs in EAST

Pellet fueling system on EAST has achieved steady-state continuous injection. But when the pellet fueling of H-mode plasma during ELM suppression with RMPs in EAST is performed , what would occur?

HU Jiansheng’s team in Institute of Plasma Physics Chinese Academy of Sciences (ASIPP) conducted a study by using pellet fueling of H-mode plasma during ELM suppression with RMPs in EAST and they obtained the density compensation and stored energy recovery in resonant magnetic perturbation.

Pellet injection is an important fueling method in the operation process of International Thermonuclear Fusion Reactor (ITER), and resonance magnetic perturbation (RMP) is an important means for ITER to mitigate the edge localized mode (ELM).

Thus, how to achieve the compatibility of these two methods is of great significance to the ITER operation in the future.

In order to solve this problem, the high confinement mode plasma with the boundary local mode completely suppressed by RMP have been fueled by deuterium pellet on EAST tokamak for the first time.

The results showed that the pellet fueling could significantly compensate the density “pump-out” effect caused by RMP, and could also restore the reduced plasma energy.

In addition, the team observed that pellet fueling was better to restore plasma energy than supersonic molecular beam injection (SMBI) under similar conditions.

The research has been strongly supported by EAST team and its collaborators, and also funded by the National Natural Science Foundation and the National Key Research and Development Program. (HOU Jilei reports)

Links to articles: https://iopscience.iop.org/article/10.1088/1741-4326/ab2bd3

Figure 1.  Temporal evolution of plasma parameters with ELM suppression by RMPs and pellet fueling (Image by HOU Jilei)

Figure 2. Comparison of pellet and SMBI fueling under RMP application (Image by HOU Jilei)