General Fusion says its LM26 fusion machine has more than tripled plasma electron temperature through mechanical compression alone, reaching about 0.72 keV, or 8.4 million degrees Celsius.
The Vancouver-based company said the result marks a key step for its Magnetized Target Fusion (MTF) technology, which aims to generate fusion conditions by compressing plasma rather than relying on powerful lasers or massive superconducting magnets.
According to the company, LM26 achieved a more than threefold increase in electron temperature during compression, bringing it closer to its next target of 1 keV, equivalent to roughly 10 million degrees Celsius.
The findings have been submitted for peer review. General Fusion said the results were obtained using its Lawson Machine 26, a large-scale demonstration system that has been operating since 2025.
Heat through compression
Unlike tokamak reactors such as ITER, which use magnetic fields to confine plasma, or laser-driven systems such as the National Ignition Facility, General Fusion’s approach relies on mechanical compression.
The company forms a magnetized plasma and then compresses it using a lithium metal liner. The compression increases temperature and density, pushing the plasma toward conditions needed for fusion reactions.
LM26 is the first MTF demonstration machine built at what General Fusion describes as a commercially relevant scale, with a diameter roughly half that of a future commercial plant.
Beyond the temperature increase, the company reported that plasma density and poloidal magnetic field strength each rose by about ten times during compression.
The machine also remained stable deep into the compression process, while researchers observed no significant contamination from the lithium liner during stable operation. Such contamination has long been considered a potential challenge for liner-based fusion systems.
Chasing fusion conditions
General Fusion said diagnostic systems including Thomson scattering and Absolute Extreme Ultraviolet (AXUV) measurements confirmed the temperature increase to approximately 0.72 keV, with an uncertainty of plus or minus 0.08 keV.
Researchers also reported an increase in neutron yield during compression, a sign that fusion reactions were occurring within the plasma. The company noted that the experiment did not achieve net energy production and described the results as preliminary pending peer review.
“We are forging a new path in fusion with our uniquely practical MTF approach. The results announced today are all key indicators of real-world progress toward our targeted technical milestones with LM26,” said Greg Twinney, Chief Executive Officer at General Fusion.
According to the company, the experimental results closely matched computer models, providing confidence that future upgrades could push the machine toward more demanding plasma conditions.
General Fusion’s next major technical milestones include reaching 1 keV, followed by 10 keV and eventually meeting the Lawson criterion, a key benchmark for sustained fusion performance.
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With over a decade-long career in journalism, Neetika Walter has worked with The Economic Times, ANI, and Hindustan Times, covering politics, business, technology, and the clean energy sector. Passionate about contemporary culture, books, poetry, and storytelling, she brings depth and insight to her writing. When she isn’t chasing stories, she’s likely lost in a book or enjoying the company of her dogs.