R&D of Common Core Technologies for HTS Coils

Abstract

The major results of conducting research and development on the common core technologies for HTS coils are reviewed. The theme has three sub-themes that are necessary for advanced superconducting devices. For the sub-theme of long coated conductors (CCs) with a high in-field I_c, a 93 m-long CC with a high I_c (min.) value of 124 A/cm-w at 77 K under 3 T was successfully fabricated by PLD. Concerning the sub-theme of generating CCs at low heat, I_c uniformity and scribing technique were both improved and uniform filament I_c values were confirmed. Additionally, lower a joint resistance than 3 nΩ was achieved using a paste that included nano-sized metals. In the sub-theme regarding the fundamental evaluation of CCs and coils, the effect of CC scribing on the decay of the shielding current was confirmed both in CCs and coils. Furthermore, a new operation process for the MRI magnet was proposed based on the above-mentioned knowledge.