Russia tests record-breaking superconductor wire for nuclear fusion

Engineers at Russia’s DV Efremov Institute of Electrophysical Apparatus (NIIEFA), part of Rosatom, have successfully tested a record-breaking high-temperature superconductor (HTSC) wire intended for the Tokamak with Reactor Technologies (TRT) fusion reactor. The tested five-meter wire, composed of 240 HTSC tapes within a copper matrix and stainless steel casing, can carry 65 kiloamperes of current in an 18 Tesla magnetic field—performance levels unprecedented in previous superconducting installations. Operating at cryogenic temperatures between 5 and 20 Kelvin, the wire demonstrated stable superconductivity during tests cooled by liquid nitrogen, confirming its suitability for the demanding electromagnetic systems of fusion reactors. This development marks a significant departure from the materials used in the International Thermonuclear Experimental Reactor (ITER), which relies on niobium-based wires operating at lower temperatures (4.5 Kelvin). The TRT wire uses yttrium-barium copper oxide tapes, enabling more compact