Abstract
The development of a current leads using YBCO superconducting rods was reviewed. The textured YBCO rods were fabricated by a zone-melt process. A high Ic value of 2,000 A was obtained by the structural control of texturing and pinning centers by Y211 particles. The highly textured structure was realized by the growth conditions of high G/R (G: Temperature Gradient and R: Growth Rate). The fine Y211 particles were obtained by the addition of the Pt powder to reduce a coarsening rate of Y211 in the liquid. The current leads were formed by the development of packaging technique for high mechanical strength and connection with the electrodes. Concerning the mechanical strength, no degradation of Ic performance due to a vibration of 15 G was achieved. Consequently, the current leads with not only high superconducting current but low thermal invasion and Joule heating was realized. It was confirmed that the total heat load could be suppressed to be 0.21 W/pair for 500 A where the high and low temperatures were controlled to be 80 and 20 K, respectively.
