Crossfield Fusion

Crossfield Fusion is an early-stage UK company exploring closed-orbit velocity-resonant confinement — a non-thermal scheme that holds ions in a narrow energy band where the fusion cross-section is highest, rather than relying on Maxwellian plasma heating.

Forget Maxwellian plasmas: hold the ions exactly at the cross-section peak and the reactor becomes orders-of-magnitude smaller.

Global electricity demand is entering an unprecedented growth phase driven by AI infrastructure, data centers, transport electrification, industrial decarbonization, water desalination, and advanced manufacturing. Solar suffers intermittency, wind capacity-factor variability, natural gas carbon emissions, conventional nuclear cost and deployment speed, and batteries energy-density and duration limits. The world requires a new source of clean, dispatchable baseload energy. Fusion represents the ultimate energy source — the challenge is making it commercially practical.

Conventional fusion plasmas waste energy heating ions over a broad Maxwellian distribution. Crossfield's approach holds ions precisely at the energy where they are most likely to fuse — an order-of-magnitude reactivity gain at the same particle inventory.

Deuterium-tritium fusion releases ~80% of its energy as 14.1 MeV neutrons, which deposit their kinetic energy in a surrounding blanket. The heat drives a conventional steam (Rankine) or supercritical-CO₂ (Brayton) turbine.

The most thoroughly understood fusion fuel cycle, highest cross-section at achievable temperatures, and proven back-end engineering (steam turbines are 19th-century technology). Trade-offs: neutron-induced materials damage, tritium handling, ~33–40% Carnot-limited efficiency.

If ion-velocity-space stability against thermalisation can be solved, the reactor scale needed for breakeven drops by orders of magnitude.

Make fusion a velocity-space engineering problem.

Prove non-thermal closed-orbit fusion is real.

• Velocity-space stability against thermalisation