| 摘要 |
PURPOSE:To stabilize an electric current flowing to connecting parts of a superconducting wire, and prevent a drift current of an electric current of an electric wire flowing to permanent current switches. CONSTITUTION:A superconducting coil device 10 has a superconducting coil 11 formed by winding a superconducting wire, four permanent current switches 20 connected in parallel to the superconducting coil 11, connecting parts 21 and 22 to connect lead wires extending from the permanent current switches 20 to lead wires 12 and 13 extending from the superconducting coil 11 and magnetic substances 23 arranged in the vicinity of the respective connecting parts 21 and 22. When an electric current flowing to the connecting parts 21 and 22 is increased, a magnetic field by the electric current is increased, and the magnetic field is further increased by a magnetizing action of the magnetic substances 23. At the same time, electric resistance of the connecting parts 21 and 22 is increased by magnetic reluctance, and as a result, the electric current flowing to the connecting parts 21 and 22 is reduced, and negative feedback acts on an increase in the electric current. |
