| 摘要 |
PROBLEM TO BE SOLVED: To allow an electric current to flow stably in a coil, reduce an AC power loss, and make a uniform normal conductive transition possible by storing, in a cryostat, a non-inductive coil made by winding superconducting wire materials like a toroid. SOLUTION: A superconducting wire material is made by laying two superconducting tapes 2a, 2b having the same length on top of each other. Four of such superconducting wire materials are joined through insulating materials 3 and reinforcing materials 4 and are wound like a toroid to form a coil 1. The four superconducting wires are so disposed that the length of the wire in which current is allowed to flow in the forward direction and the length of the wire in which current is allowed to flow in the backward direction may be the same. The superconducting tapes 2a, 2b are Ag sheathed (Bi, Pb)2Sr2 Ca2Cu3Oy(Bi2223) oxide superconducting tapes. As for the reinforcing material 4, a substance having a relative permittivity nearly the same as that of liquid nitrogen is used. The reinforcing materials 4 and the wires are insulated by being wound with the insulating material 3 such as insulating paper, an FRP plate, and a Kapton tape put between. |
