Proxima Fusion has unveiled its design for a fusion power plant based on a quasi-isodynamic (QI) stellarator configuration. The Munich-based startup, a direct spin-off from the Max Planck Institute for Plasma Physics (IPP), claims its approach offers the most viable path to commercial fusion energy. The design leverages insights from the Wendelstein 7-X (W7-X) experiment, the world's largest and most advanced stellarator. Proxima projects a six-year timeline to construct its first-of-a-kind demonstration device, aiming to capitalize on recent advances in magnet technology and computational plasma modeling. Source: Proxima Fusion

The core of Proxima's strategy is the QI stellarator, a concept computationally optimized to minimize neoclassical transport and achieve plasma confinement comparable to tokamaks while avoiding their inherent vulnerability to disruptive instabilities. Unlike tokamaks, which rely on a large, induced plasma current for confinement, stellarators generate their twisted magnetic fields entirely with external coils. This design principle allows for intrinsically steady-state operation, a critical requirement for a commercial power plant. The W7-X experiment at IPP has served as the primary validation platform for the QI concept, demonstrating stable high-performance plasmas and confirming the theoretical models underpinning the design. Source: Proxima Fusion

Unlike tokamaks, which rely on a large, induced plasma current for confinement, stellarators generate their twisted magnetic fields entirely with external coils.

A key enabling technology for the Proxima design is the use of high-temperature superconducting (HTS) magnets. These magnets can generate stronger magnetic fields more efficiently than the low-temperature superconducting coils used in W7-X, permitting a more compact and economically feasible reactor. The company's engineering team, which includes personnel with experience from MIT, Google, and SpaceX, is tasked with integrating these advanced magnets into the complex, computationally-derived stellarator geometry. This technological step is crucial for moving from the physics-experiment scale of W7-X to a commercially relevant power-producing device. Source: Proxima Fusion

The announcement follows a €20 million pre-seed funding round Proxima Fusion secured in 2023, one of the largest for a European fusion startup. The company's development efforts are also situated within a supportive national policy environment, highlighted by a recent €1 billion investment into fusion energy by the German government. Proxima's approach represents a significant entry in the growing private fusion sector, which is increasingly pursuing alternative confinement concepts beyond the mainline tokamak path followed by large public projects like ITER. The company's focus on engineering a power plant based on a scientifically validated plasma concept distinguishes its strategy. Source: Proxima Fusion