Scientists have achieved an electrical current of 100,000 amperes, which they claim is by far the highest in the world.
The advance was made possible by assembling the state-of-the-art yttrium-based high-temperature superconducting tapes to fabricate a large-scale magnet conductor.
The National Institute for Fusion Science (NIFS), of the National Institutes of Natural Sciences (NINS) in Japan, is undertaking the development of a high-temperature superconducting coil that is appropriate for the fusion reactor magnet.
Using the state-of-the-art yttrium-based high-temperature superconducting tapes which have been developed and produced in Japan through the new technique that simply stacks the tapes, NIFS manufactured a conductor of exceptional mechanical strength.
For the conductor joints, which are important for the production of the large-scale coils, NIFS developed low-resistance joint technology through collaborative research with Tohoku University.
As a result of the prototype conductor test, at the absolute temperature of minus 253 degrees Celsius the electrical current exceeds 100,000 amperes.
The overall current density exceeds 40 Ampere per square millimetre including the jackets, and this value is of practical use for manufacturing large-scale fusion reactor magnets. This result is of global importance.
"We use 54 yttrium-based high-temperature superconducting tapes. Each tape is 10 mm in width and 0.2 mm in thickness," researchers said.
The electrical current flows only through one area. Together with the substrate used for this type of tape that is exceptional in strength and flexibility, by surrounding this area by a copper jacket and a stainless steel jacket an extremely strong conductor is produced. The current is induced by magnetic induction.
