A team led by the University at Buffalo has developed the highest-performing high-temperature superconducting (HTS) wire segment to date, opening new possibilities for harnessing magnetic forces and potentially transforming energy infrastructure and even enabling commercial nuclear fusion. The breakthrough is detailed in the latest issue of Nature Communications.
The new HTS wire, based on rare-earth barium copper oxide, can transmit electricity without resistance at temperatures higher than those required for traditional superconductors. It covers a wide range of magnetic fields and operational temperatures from 5 Kelvin to 77 Kelvin, surpassing the temperature range of conventional superconductors.
At 4.2 Kelvin, the wire can carry 190 million amperes per square centimeter in zero external magnetic field (self-field) and 90 million amperes per square centimeter in a 7 Tesla magnetic field. At 20 Kelvin, which is expected for commercial nuclear fusion applications, the wire can still carry over 150 million amperes per square centimeter in self-field and over 60 million amperes per square centimeter in a 7 Tesla magnetic field.
In terms of critical current, which is the maximum DC current, a superconductor can carry without resistance, the wire segment, 4 millimeters wide, can handle 1,500 amperes in self-field at 4.2 Kelvin and 700 amperes in a 7 Tesla magnetic field. At 20 Kelvin, it can carry 1,200 amperes in the self-field and 500 amperes in a 7 Tesla magnetic field.
Remarkably, despite having a thin film thickness of only 0.2 micrometers, the HTS wire supports currents comparable to commercial superconducting wires that are nearly ten times thicker. The wire also demonstrates impressive pinning capabilities, with a pinning force of about 6.4 teranewtons per cubic meter at 4.2 Kelvin and 4.2 teranewtons per cubic meter at 20 Kelvin, both in a 7 Tesla magnetic field.
This represents the highest reported values for critical current density and pinning force across all magnetic fields and operating temperatures to date.
