The United Kingdom Atomic Energy Authority (UKAEA) and Stellarex Energy have formalized a collaboration through a Memorandum of Understanding to advance stellarator-based fusion energy. The agreement, announced May 13, 2026, establishes a framework for the two organizations to combine UKAEA's public-sector research infrastructure and operational experience with Stellarex's private-sector stellarator development program. Stellarex, a spin-out from the Princeton Plasma Physics Laboratory, is focused on a proprietary quasi-axisymmetric (QA) stellarator design intended to improve plasma confinement and stability. Source: UKAEA

This partnership will leverage UKAEA's extensive expertise gained from operating the Joint European Torus (JET) and its ongoing Spherical Tokamak for Energy Production (STEP) program. Key areas for collaboration include advanced materials science, tritium fuel cycle technologies, and remote maintenance systems, all critical for the design and operation of a future fusion power plant. For Stellarex Energy, access to UKAEA's facilities and personnel at the Culham Science Centre provides a significant opportunity to de-risk technical challenges associated with its planned prototype device, SX-1. Source: UKAEA

[Source: UKAEA](https://www.morningstar.com/news/pr-newswire/20260513ny58495/ukaea-and-stellarex-energy-to-advance-fusion-power-development)

The collaboration centers on the stellarator concept, a magnetic confinement approach that uses complex, externally-wound magnetic coils to twist the plasma, avoiding the large plasma-driven currents required in tokamaks. Stellarex's focus on a quasi-axisymmetric configuration is particularly notable; QA stellarators are computationally designed to have a hidden symmetry in their magnetic field strength, aiming to achieve tokamak-like particle confinement while retaining the intrinsic steady-state operational advantages of the stellarator. This design philosophy represents a modern approach to overcoming historical stellarator performance limitations. Source: UKAEA

The agreement exemplifies a growing trend of public-private partnerships within the global fusion ecosystem, as seen across the private fusion industry. Such collaborations allow national laboratories to support a broader portfolio of fusion concepts and technologies, accelerating overall progress. For private developers, these partnerships provide access to invaluable, and often irreplaceable, experimental infrastructure and specialized knowledge that would be capital-intensive to replicate. This model enables a symbiotic relationship where public investment in fundamental research is amplified by targeted, commercially-driven innovation. Source: UKAEA

The immediate next steps following the MOU will involve defining specific joint projects and work packages. The performance of Stellarex's planned SX-1 prototype will be a key development to monitor, as it will serve as the first integrated test of the company's QA plasma configuration and enabling technologies. The success of this collaboration will be measured by the transfer of UKAEA's operational knowledge into the SX-1 design and the subsequent experimental results that validate the physics basis of the Stellarex concept. Source: UKAEA