AbstractThe composite superconductor called Design-M for the TOKI-MC has been designed as part of a chain of research and development programs. The conductor must be conductive to the requirements of electrical and mechanical properties. The designed conductor can be divided into three main parts: a five-layered and compacted superconducting cable, four copper-clad 5-nines pure aluminum stabilizers and a half-hard copper sheath. These parts are soldered together. The surface of the copper sheath is coated with copper oxide to assist heat transfer toward liquid helium. The operating current is designed to be 20 kA in a magnetic field of 8 T at a temperature of 4.2 K. The conductor has been manufactured in total lengths of about 900 m, and approximately 2000 kg in weight. Technical improvements have been made and production facilities for assembly have been set up for mass-scale production. Electrical and mechanical properties have been investigated.
Research and development of superconductors and superconducting coils for the Large Helical Device