| 摘要 |
PROBLEM TO BE SOLVED: To provide an induction current collection system, which reduces the fluctuations of a magnetic field, which are exerted on an induction current collection coil by an eddy current which is made to flow through a vacuum heat insulating container, and has a high current collection power, in a superconducting magnet, which is used for an on-board current collection of a magnetic leviation railway. SOLUTION: This superconducting megnet consists of a superconducting coil 11, a housing container 12 for housing the coil 11, a radiant heat shield 18, which is located on the outside of the container 12 and shields radiant heat, and a vacuum heat insulating container 14 for housing the above coil 11, container 12, shield 18 and container 14. In this case, the surface, which faces a ground coil, of the container 14 is constituted of layers consisting of tow kinds or more of materials having different electrical resistivities and is constituted of the layer consisting of the material having the high electrical resistivity as it approaches the side, which is close to the ground coil. Thereby, the fluctuations of a magnetic field, which are exerted on the container 14 by an eddy current, which is made to flow through the container 14, is lessened. As a result, a superconducting magnet for magnetic levitation railway use, which contributes to the enhancement of the current collecting power of a current collecting coil, is high in rigidity, is high in strength, is lightweight and has also a high magnetic field shielding effect, can be provided. |
