Journal Article

Taming harmful bursts and heat flux in high-confinement tokamak plasmas

Kim, SangKyeun, Maingi, Rajesh, Moser, Auna L., Osborne, Thomas H., Yang, SeongMoo, Wang, Huiqian Q., Effenberg, Florian, Wilks, Theresa M., Wilcox, Robert S., Gu, S., Navarro, Marco X., Jia, M. N., Leonard, A. W., Paz-Soldan, Carlos, Eldon, David, Lasnier, C. J., Meng, L. Y., Ma, Xinxing, Sun, Y. W., Hu, Q. M., Ceelen, Lennard, Frerichs, Heinke, Bortolon, Alessandro, Gong, X. Z., Ye, C., Wang, H. H., Shafer, Morgan W., Scotti, Filippo, Logan, Nikolas C., Ma, Q., Li, K. D., Wang, Liang

2025

Overview

A major challenge in tokamak fusion research is first-wall erosion caused by steady heat loads and sudden energy bursts known as edge-localized modes. Divertor detachment reduces steady-state heat flux, while resonant magnetic perturbations can suppress these instabilities. However, integrating the two has been difficult because they require conflicting operating conditions. Here we demonstrate simultaneous achievement of resonant magnetic perturbations mitigated small edge-localized modes and impurity seeded partial divertor detachment in plasmas with an ITER-similar shape on the DIII-D tokamak. Experiments and simulations show that resonant magnetic perturbations facilitate detachment by redistributing particles, lowering the core density and increasing the scrape-off layer density, thereby reducing the amount of injected gas required. Cooling-gas injection eliminates the secondary heat-flux peak created by three-dimensional magnetic lobes, while edge cooling weakens the plasma response to the applied magnetic fields. These advances illustrate a viable pathway for integrating edge stability control with power exhaust in future fusion reactors.

• Publisher: Nature Publishing Group