General Fusion Group Ltd. (NASDAQ: GFUZ) announced it has measured electron temperatures exceeding 1 keV, or approximately 12 million degrees Celsius, using its large-scale Lawson Machine 26 (LM26) demonstration device, which the company describes as a first for low-speed plasma compression technology.

The result was measured using Thomson scattering diagnostics in collaboration with the UK Atomic Energy Authority (UKAEA), with corroborating data from the company's absolute extreme ultraviolet (AXUV) diagnostic system. The Thomson scattering measurement recorded approximately 1.1 keV just prior to peak compression, while the AXUV system recorded approximately 1.2 keV during peak compression. The company also observed ion heating to approximately 0.46 keV, representing up to a twofold increase above the starting ion temperature.

The results were detailed in two technical papers submitted for peer review, one co-authored with UKAEA and one authored separately by General Fusion covering AXUV and ion heating data.

General Fusion said the achievement represents the first of three technical milestones planned for the LM26 program. The company stated it is now upgrading LM26 to pursue the second milestone of 10 keV plasma temperature, with a third milestone targeting the Lawson criterion — the combination of temperature, density, and energy confinement time required for net fusion energy in the plasma.

The company said its Magnetized Target Fusion approach uses relatively low-speed mechanical compression measured in milliseconds, compared to microsecond or nanosecond timescales used by other compression technologies, and does not use superconducting magnets or high-powered lasers.

General Atomics Energy Group is advising on diagnostic systems for the next milestone. General Fusion said it aims to begin operating a first-of-a-kind commercial fusion plant around 2035, though that timeline carries significant uncertainty as outlined in the company's forward-looking disclosures.

CEO Greg Twinney said the result "gives us greater confidence as we advance toward our next target of 10 keV."