In what is being hailed as another first for commercial fusion, UK-based Tokamak Energy has built a set of new high-temperature superconducting (HTS) magnets to be assembled and tested at the firm’s Demo4 facility.
The magnets are used to create the strong magnetic fields needed to confine and control the plasma which is several times hotter than the Sun.
In order to test the new HTS magnets Tokamak Energy will utilise the 44 newly built individual magnetic coils at the Demo4 facility.
Demo4 will comprise 14 toroidal field (TF) limbs and a pair of poloidal field coil stacks to form a cage-shaped structure.
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Strong magnetic fields are generated by passing large electrical currents through arrays of electromagnet coils that will surround the plasma in future power plants.
The magnets are wound with HTS tapes, which are multi-layered conductors made mostly of strong and conductive metals, but with an internal coating of ‘rare earth barium copper oxide’ (REBCO) superconducting material.
According to Tokamak Energy, Demo4 will have a magnetic field strength of over 18 Tesla, nearly a million times stronger than the Earth’s magnetic field.
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Dr Rod Bateman, HTS magnet development manager at Tokamak Energy, added: “Demo4 will allow us to create substantial magnetic forces and test them in fusion power plant-relevant scenarios. Importantly, it will substantially progress the technology readiness level of HTS magnets as a key part of our mission to demonstrate grid-ready fusion in the early 2030s.”
Full assembly at Tokamak Energy’s headquarters in Milton Park, near Oxford, will complete this year and testing will extend into 2024, informing designs and operational scenarios for its advanced prototype, ST80-HTS, and subsequent fusion power plant, ST-E1.
