Fabrication of ${\rm Gd}_{1}{\rm Ba}_{2}{\rm Cu}_{3}{\rm O}_{\rm x}$ Coated Conductors for HTS Cables

We have been fabricating Gd₁Ba₂Cu₃O_x (GdBCO) coated conductors (CCs) on textured clad-type substrates by using pulsed laser deposition (PLD) method for high temperature superconducting (HTS) power cables. In this project, numerous numbers of CCs are required for fabricating a 66 kV class, 3-in-One HTS cable and for the evaluation of its properties. In order to achieve this, it is important to ensure the stable production and the high-throughput manufacturing. In this work, we have newly installed a high power laser of 300 W for the PLD equipment, which has 1.66 times higher power than the previous one. As a result, the stability of manufacturing and the production rate were greatly improved. In addition, we have adopted a wide tape approach using 30 mm width substrates to increase the throughput. Moreover, we have optimized deposition condition for a seed layer by electron beam (EB) evaporation method, then the maximum I_c value for a short sample has achieved 497 A/cm at 77 K in the self-field. With this improved process, long GdBCO tapes with high I_c have been successfully fabricated.