Superconducting circuit, production method of superconducting joints, superconducting magnet, and production method of superconducting magnet

摘要

A superconducting circuit including a superconducting joint (13) that joints a niobium titanium superconducting wire (12) having a structure where a filament (18) made of niobium titanium alloy is arranged in a matrix (19) made of copper or copper alloy and other superconducting wire (12), in which a volume ratio or a surface density of an α-Ti precipitation in the niobium titanium alloy of the filament (18) in the superconducting joint (13) is smaller than the volume ratio or the surface density of the α-Ti precipitation in the niobium titanium alloy of the filament (18) in the niobium titanium superconducting wire (12) in a portion other than the superconducting joint (13).