Proxima Fusion Signed Two Deals in Tokyo. Neither Is an Order, but Both Show What a Fusion Plant Needs.

The German startup Proxima Fusion wants to build a fusion power plant. To do that, it needs a few tens of thousands of kilometers of superconducting tape. On Oct. 28, in Tokyo, it took a step toward finding someone to make it.

Proxima signed two memorandums of understanding with Japanese companies during German Chancellor Friedrich Merz's visit to Japan. The first is with Fujikura, a cable and optical-fiber maker, on high-temperature superconducting (HTS) tape. The second is with Kyoto Fusioneering, on plasma-heating systems and fuel-cycle technology.

The Tape Deal

Magnets are the heart of a stellarator, and the magnets run on HTS tape. Proxima says its Alpha demonstrator would use about 20,000 kilometers of it. Each commercial Stellaris power plant would need about 40,000 kilometers.

Under the Fujikura memorandum, the two sides will study whether it makes sense to supply that tape through Lower Saxony, including a possible factory in the region. The Next Web is explicit about the limits: neither agreement is a firm order or a commitment to build. XenoSpectrum adds that no final investment decision or production capacity has been announced, and that the tape figures are Proxima's own demand estimates.

Fujikura's reported role has a context. The Next Web notes that Commonwealth Fusion Systems reportedly ordered more than 10,000 kilometers of tape from Fujikura last month. Fusion companies are lining up at the same supplier.

The Heating Deal

The Kyoto Fusioneering agreement continues and expands joint work on gyrotrons, the high-power devices that heat plasma with microwaves, and on fuel-cycle technologies. Kyoto Fusioneering is slated to contribute to commercial deployment in Germany, including through the federal Fusion Hubs initiative, though one outlet says the companies are only looking at participating. Proxima's team visited Kyoto Fusioneering's Tokyo Research Center as part of the trip.

Who Proxima Is

Proxima spun out of the Max Planck Institute for Plasma Physics and builds on the Wendelstein 7-X stellarator. It has about 200 employees and an industrial group called the Alpha Alliance with more than 50 partners. Its plan is an Alpha demonstrator in the early 2030s that aims to produce more energy than goes into the plasma, followed by Stellaris, a commercial plant. Reports differ on when: "later that decade" in one account, the late 2030s in another. The Next Web reports Proxima raised €411 million in July at a €2.4 billion valuation.

CEO Francesco Sciortino put the idea in a line that fits the whole trip: "The global race to fusion will be won in factories and supply chains."

Our Take

It's tempting to dismiss memorandums of understanding, and in a narrow sense you should. They don't commit anyone to buy anything.

But read them as a to-do list. Proxima has just told you the two hardest things on its list that aren't physics: a few tens of thousands of kilometers of superconductor, and a reliable way to heat the plasma. Those are the same kinds of bottlenecks that show up in this week's 3D-printed tungsten tile test and in the Commerce Department's chip funding for Helion and CFS. If you want to know who's serious about fusion, watch who's signing deals with the people who make the parts.

What We Cannot Conclude

• None of this is a purchase. Both agreements are memorandums of understanding, and no value has been disclosed.
• We can't say commercial power is near. Proxima's own timeline puts a demonstrator in the early 2030s, and a plant later.
• The tape numbers are Proxima's estimates. They're demand projections, not shipments.
• Accounts differ on some details. The Stellaris date, the exact wording on Fusion Hubs, and the description of Kyoto Fusioneering's fuel work vary between outlets.
• We haven't compared the stellarator design against its rivals. Our fusion companies comparison covers the field more broadly.

Why It Matters

• Fusion's second race is about suppliers. Magnet tape, heating systems and wall materials are now the news.
• Japan is a key part of the chain. Fujikura and Kyoto Fusioneering show up repeatedly in Western fusion plans.
• Governments are using fusion as industrial policy. The signing was timed to a chancellor's visit, and Germany has said it wants the first fusion power plant on its soil.
• A memorandum is a beginning, not a contract. Watch for an actual order or a factory decision.