Fusion energy promises a future of abundant, low-carbon power and large-scale superconducting magnets are at the heart of enabling a (magnetic confinement based) fusion power station to generate power. STEP Fusion (Spherical Tokamak for Energy Production) is developing the UK’s prototype fusion powerplant at West Burton in Nottinghamshire, and recent advances are helping bring that vision closer to reality and bringing the project closer to the ambition of building the prototype by 2040.
Case Study: Power Under Pressure – HTS Cable sets new performance record
STEP Fusion’s high-temperature superconducting (HTS) cable is the backbone of its fusion magnets. It was put to the test at the SULTAN facility in Switzerland. The cable carried over 90,000 amps (a standard household kettle uses about 10 amps) under intense magnetic fields and temperatures
Fusion fact: The HTS cables were able to withstand mechanical forces equivalent to 50 cars pressing down on every metre of cable.
Even after 1,400 stress cycles, the cable showed no signs of wear, a record-breaking performance for an HTS cable cycled at such a high current at the SULTAN facility. The result in the first step in validating the cable design being developed for use in STEP’s future magnet systems.
Developed in collaboration with Seoul National University, South Korea and PowerNix Co. Ltd, this cable design surpasses previous international benchmarks, proving STEP Fusion’s design is robust enough for real-world fusion conditions.
Why it matters:
Stronger HTS cables are needed for building a fusion powerplant that works reliably and efficiently.
It also shows how STEP Fusion is combining UK innovation, international collaboration, and cross-sector expertise to solve fusion’s toughest challenges.
By validating designs through simulation, prototyping, and testing, STEP Fusion is building confidence in the technologies that will power the future and strengthening the UK’s position as a global leader in fusion energy.
