Max Planck spin-off reveals 'the most feasible' fusion reactor proposal in the world.

      The German startup Proxima Fusion, which boasts a team of engineers from prominent organizations such as MIT, Google, SpaceX, and McLaren, has introduced a design for a fusion energy reactor that it believes could be the fastest path to commercially viable fusion power. Named Stellaris, this reactor is a quasi-isodynamic (QI) stellarator employing high-temperature superconducting (HTS) technology. It utilizes intricately twisted magnetic fields to confine heated plasma, thereby creating the necessary conditions for fusion reactions.

      “Stellaris is engineered for continuous operation and is inherently stable,” explained Francesco Sciortino, Proxima’s co-founder and CEO, in a statement to TNW. “No other fusion power plant design has been proven capable of this.”

      The design of Stellaris is built upon the Wendelstein 7-X, the largest stellarator globally, which is situated at the Max Planck Institute for Plasma Physics in Germany. While the Wendelstein 7-X was primarily developed for research purposes, Stellaris has the potential to one day provide power to the electrical grid.

      Proxima aims to bring its vision to fruition with the first demonstrator, named Alpha, anticipated to be completed within the next six years. According to Sciortino, Alpha will be the first fusion device to demonstrate net energy production in a steady state. This machine will serve as the foundation for Proxima’s initial 1GW fusion reactor, which the company hopes to see operational in the 2030s.

      Stellarators offer several benefits over the more commonly used tokamak design, which is being employed in the ITER mega project currently under construction in France. They require less energy to function and exhibit greater stability. However, they come with the downside of complexity, making them challenging to design and construct. This complexity led to their being largely abandoned in favor of tokamaks in the 1960s. Nevertheless, advancements in computational technology are bridging that gap.

      An AI-enhanced reactor design

      Similar to sectors such as automotive and aerospace, Proxima leverages AI supercomputers to quickly iterate the most effective fusion reactor designs based on crucial factors like cost, material availability, and efficiency. This strategy allows Proxima to bypass the need for numerous prototypes and leap directly into developing a functional demonstrator.

      “Understanding complex geometry and its implications is vital in stellarators,” Sciortino noted. “AI is assisting Proxima in identifying patterns that lead to simpler, faster, and less expensive designs.”

      Stellaris is designed to produce more energy per unit volume than any existing stellarator. The use of high-temperature superconducting (HTS) magnets enables stronger magnetic fields, resulting in reactors that are smaller, quicker to construct, and more efficient. This approach also lowers costs for both construction and operation. Additionally, Stellaris is made from readily available materials, meaning it can be built using current supply chains, according to the company. Comprehensive details of the reactor were released today in Fusion Engineering and Design.

      The visuals of Stellaris display a distinctive twisting design. Credit: Proxima Fusion

      Proxima, based in Munich, made headlines in 2023 as the first company to emerge from the renowned Max Planck Institute for Plasma Physics, one of the leading centers for fusion research globally. This institute is dedicated exclusively to fusion and has a greater number of plasma physicists than MIT.

      Last year, Proxima secured €20 million in funding as it seeks to transform the complex physics of fusion into a viable business.

      “When Proxima began its journey, the founders stated, ‘This is achievable, and we’ll demonstrate it to you,’ and they have,” remarked Ian Hogarth, a partner at Plural, one of Proxima Fusion’s initial investors. “Stellaris establishes QI-HTS stellarators as the forefront technology in the global competition for commercial fusion.”