Inside a Fusion Star: National Geographic Photographer Crawls Through the Wendelstein 7‑X

Inside the Wendelstein 7‑X

Wearing a spotless white lab suit with matching shoes and gloves, National Geographic Explorer Paolo Verzone squeezed through an opening barely wider than his body to gain a rare vantage point inside the Wendelstein 7‑X. Visiting the Max Planck Institute for Plasma Physics in Greifswald, Germany, on a November maintenance day, Verzone described the sensation as “entering into a star.”

How It Works

The torus‑shaped chamber where Verzone stood is filled with plasma when the device runs — a superheated, electrically charged gas warmed to tens of millions of degrees Celsius. Surrounding superconducting magnets are chilled to roughly −269 °C (close to absolute zero), creating an extreme temperature contrast that allows researchers to confine and study the plasma.

Those conditions aim to trigger nuclear fusion: lightweight atoms such as hydrogen combine under intense heat and pressure to form heavier atoms and release energy — the same fundamental process that powers the Sun. If harnessed, fusion could provide large quantities of low‑emission electricity.

Stellarator Design And Achievements

The Wendelstein 7‑X is a stellarator, a class of fusion device that uses intricately twisted magnetic coils — rather than driven plasma currents used by tokamaks like ITER — to shape magnetic field lines and keep particles confined. This sculptural coil geometry helps keep the plasma on track so particles do not collide with the reactor walls.

Wendelstein 7‑X recently set a notable operational milestone by maintaining superheated plasma for 43 seconds, an achievement that highlights the stellarator’s potential for long‑duration confinement. About 8,000 graphite tiles and water‑cooled steel plates line the helical interior to protect the structure from heat and particle bombardment during experiments.

Limits And Next Steps

Scientists emphasize that Wendelstein 7‑X has not yet delivered usable fusion power. Current experiments are focused on validating the stellarator concept and plasma stability. Even if researchers achieve a sustained reaction that produces more energy than it consumes, significant engineering hurdles remain — including how to extract the fusion energy from the confined plasma and convert it into electricity suitable for the grid. Teams worldwide are actively researching those next steps.

“It’s like you are entering into a crypt of a cathedral,” Paolo Verzone said of the inner chamber, calling it a rarely visited sanctum that invites reflection on the sublime. Physicist Josefine Proll added, “In the last decade, there have been such cool advancements... I think there is finally more momentum behind it.”

The Wendelstein 7‑X stands as both a technical testbed and an evocative piece of engineering — part scientific instrument, part cathedral‑like space that captures the imagination while advancing fusion research.