https://www.sciencedaily.com/releases/2018/11/181105105445.htm

The team completed construction of Wendelstein 7-X, the world's most advanced superconducting stellarator, in 2015 and, since then, scientists have been busy studying its performance.

"The advantage of stellarators over other types of fusion machines is that the plasmas produced are extremely stable and very high densities are possible," said Dr. Novimir Pablant, a U.S. physicist from the Princeton Plasma Physics Laboratory, who works alongside a multinational team of scientists and engineers from Europe, Australia, Japan, and the United States (the U.S. collaboration is funded by the Department of Energy).