2010 年 45 巻 1 号 p. 22-26
Dy-Ba-Cu-O is an ideal material for current leads because it has a low thermal conductivity and a high critical current density of 77 K in high magnetic fields. In this study, current carrying properties of Dy-Ba-Cu-O bulk current leads under the cryocooler-cooled condition have been investigated. The current leads consisted of a Dy-Ba-Cu-O bulk superconductor 40 mm x 3 mm x 0.8 mm, copper electrodes and a protective glass-fiber-reinforced-plastic sheet. Large currents of more than 400 A could be transported through the current leads at 77 K and the current-carrying capacity of the current leads increased with decreasing cooling temperature.