Proxima Fusion Advances Stellarator Design for Nuclear Fusion Energy

Proxima Fusion is working on a stellarator, a device designed to contain burning plasma for nuclear fusion through a complex shape with twists and curves. This approach contrasts with the more common tokamak, which uses a doughnut-shaped container. The company aims to create abundant, emission-free electricity by replicating the Sun's energy-producing reaction on Earth.

Fusion involves heating hydrogen isotopes like tritium and deuterium to form a hot plasma, which must be controlled to sustain the reaction. High temperatures, exceeding those on the Sun, are required without the Sun's gravitational forces.

to Francesco Sciortino, co-founder and CEO of Proxima Fusion, the stellarator's design could make plasma easier to control than in tokamaks, describing it as a simple machine once built. The company is developing a stellarator named Alpha, drawing from decades of research at the Max Planck Institute for Plasma Physics and its W7-X device.

Building stellarators is more difficult and expensive due to their intricate shapes. Proxima Fusion recently secured €400 million from the state of Bavaria and is seeking over a billion dollars from the federal government, with a decision expected next year.

The Fusion Industry Association reports 53 groups developing fusion technology. One tokamak-based project is the UK's Step, planned for a former coal-fired power station site in West Burton, Yorkshire, backed by the UK government. Ryan Ramsey, director of Organisational Performance at Step, stated that tokamaks benefit from extensive experimental data and simpler magnetic geometry, aiding manufacturability and cost.

Timeline Proxima Fusion is constructing a prototype magnetic coil for testing next year, followed by 40 more for Alpha. A magnet factory is in early development to support rapid production by 2028 or 2029. The company highlights Germany's manufacturing expertise, including 550,000 CNC machinists, compared to 350,000 in the United States.

This capability is essential for machining high-precision steel in the magnets. Proxima Fusion plans to use lessons from Alpha to design Stellaris, a fusion power plant. Across Europe, suppliers contribute to the effort, potentially positioning the region in future fusion industry leadership.