A Canadian company pursuing magnetized target fusion, a hybrid approach that compresses magnetized plasma using mechanical pistons. General Fusion is building a demonstration plant at the UK Atomic Energy Authority's Culham campus.
General Fusion was founded in 2002 by Michel Laberge, a physicist and former laser engineer, in Burnaby, British Columbia, Canada. Laberge conceived of a fusion approach that would combine elements of magnetic and inertial confinement, using mechanical compression of a liquid metal liner to heat and compress a magnetized plasma target.1
The company was an early entrant in the modern wave of private fusion ventures, predating the post-2010 surge of startup activity by nearly a decade.
Magnetized target fusion (MTF), sometimes called magneto-inertial fusion, occupies a middle ground between the two dominant fusion paradigms. In General Fusion's implementation, a compact toroid plasma (a spheromak) is injected into a cavity within a vortex of liquid metal (lithium or a lithium-lead alloy). An array of pneumatically driven pistons then simultaneously compresses the liquid metal, which in turn compresses and heats the plasma to fusion conditions.2
The pulsed nature of the system means it would fire repeatedly, like an engine, with each compression cycle lasting microseconds and the repetition rate determining the average power output.
General Fusion has raised over $300 million from investors including Jeff Bezos (through Bezos Expeditions), Shopify founder Tobias Lütke, Cenovus Energy, Chrysalix Venture Capital, and several sovereign and institutional investors. The Government of Canada has also provided funding support.3
In June 2021, General Fusion announced a partnership with the UK Atomic Energy Authority (UKAEA) to build its Fusion Demonstration Plant (FDP) at the Culham Science Centre in Oxfordshire, England — the same campus that houses the JET and MAST-Upgrade tokamaks.
Over two decades, General Fusion has demonstrated several component technologies: plasma injector systems capable of forming compact toroids, precision-synchronized piston arrays, and liquid metal vortex formation. However, the company has not yet demonstrated the integrated cycle of plasma injection, compression, and fusion in a single device.4
In 2023, the company underwent a leadership transition. Christofer Mowry, who had served as CEO since 2015, departed, and the company restructured. Greg Twinney was appointed CEO in 2024. The company also scaled back some projections about the timeline to a commercial reactor.5
General Fusion represents one of the most unconventional approaches in the private fusion landscape. Its mechanical compression concept, if validated, could offer a path to fusion energy using relatively low-cost, replaceable components. The primary technical risk remains demonstrating that all subsystems — plasma formation, liquid metal vortex, and synchronized piston compression — can work together reliably at the required precision and repetition rate.