MRO Magazine

General Fusion forges ahead on its Magnetized Target Fusion technology

October 25, 2022 | By Monica Ferguson

Photo: General Fusion.

Photo: General Fusion.

Construction of General Fusion’s demonstration machine, which is being built at the UK Atomic Energy Agency’s Culham Campus, advanced with the fabrication of an at-scale fusion vessel trial ring by Sheffield Forgemasters.

This component will confirm the specifications of the thick-walled fusion vessel, designed to withstand the high temperatures and compressive forces needed to create fusion energy with General Fusion’s practical technology – Magnetized Targeted Fusion (MTF).

The vessel is designed to be modular, made up of 11 steel rings bolted together on site. In the future, this method will enable General Fusion to deploy its commercial machines quickly.

The trial ring’s specifications are the same as the rings planned for the fusion demonstration machine and allow the engineering team to validate the performance of the high-strength steel alloy, finalize the vessel design, and confirm the manufacturing process.


The fusion demonstration machine will create fusion conditions, including achieving a temperature of 100 million degrees Celsius in a power-plant-relevant environment. Its results will provide the information needed to design and build a commercial pilot plant that generates electricity at an affordable price.

“Sheffield Forgemasters brings to this project over 200 years of expertise creating complex steel components,” said Greg Twinney, CEO, General Fusion. “Teaming up with world-leading specialists allows us to focus on our commercialization plan and stay on pace to generate zero-carbon electricity by the early 2030s.”

To create the trial ring, a large steel ingot was forged in an open-die press, forming the steel into a donut shape with a diameter of just over three metres. Next, the ingot will be rolled and expanded into a larger, thinner ring; at this point, the ring will span 7.6 metres in diameter. Then, 56 holes will be drilled into the ring. These replicate the holes that will transmit high-pressure gas from the compression drivers to a spinning interior rotor in the fusion demonstration machine. The pressure change will push smaller pistons to collapse General Fusion’s proprietary liquid metal liner around hydrogen plasma and create fusion.

The final trial ring will weigh 42 metric tons. Sheffield Forgemasters’ engineering team will complete non-destructive testing on the trial ring, which can include visual, ultrasonic, dye-penetrant and magnetic particle inspection, as well as eddy current testing.


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