The W7-X stellarator has moved mankind a step closer to nuclear fusion

By mimicking how the sun reacts atoms together in a process called nuclear fusion, scientists believe it would be possible to create a potentially limitless source of clean, renewable energy.

Although no one has yet succeeded in this mission, scientists are now a step closer.

Fusion energy research has in the past 40 years focused primarily on the tokamak concept, but recent advances in plasma theory and computational power have led to renewed interest in stellarators.

Most recently, the Wendelstein 7-X (W7-X) stellarator (pictured), a type of device that uses magnetic fields to confine the hot plasma that fuels fusion, has shown great promise.

Physicist Sam Lazerson of the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) has teamed with German scientists to confirm that the Wendelstein 7-X (W7-X) fusion energy device called a stellarator in Greifswald, Germany, produces high-quality magnetic fields that are consistent with their complex design.

The findings, published in the November 30 issue of Nature Communications, showed that the deviation of the carefully tailored topology of nested magnetic surfaces needed for good confinement of the hot plasma was less than one part in 100,000. Such results could become a key step toward verifying the feasibility of stellarators as models for future fusion reactors.

W7-X, for which PPPL is the leading US collaborator, is the largest and most sophisticated stellarator in the world. Built by the Max Planck Institute for Plasma Physics in Greifswald, it was completed in 2015 as the vanguard of the stellarator design. Other collaborators on the US team include DOE’s Oak Ridge and Los Alamos National Laboratories, along with Auburn University, the Massachusetts Institute of Technology, the University of Wisconsin-Madison and Xanthos Technologies.