| 摘要 |
PROBLEM TO BE SOLVED: To provide the title superconductive magnet capable of suppressing the expansion of magnetic field without using an iron shield at all. SOLUTION: A superconductive coil 8 is composed on the outer periphery of an inner tube inside a cylindrical cryostat 7 in dual tube structure to fill the cryostat 7 with liquid helium 6 so that the cryostate 7 may be encircled with a heat insulated structure to be shut off from external heating. Next, a cylindrical supporting member 15 made of high thermal conductive material is inserted into the inner periphery of an outer tube part simultaneously engraving plural trenches 16 extending in the axial center direction on the outer periphery of the supporting member 15 at proper intervals to be engaged with superconductive wires 17 reaching the superconductive state at the temperature cold insulated by the liquid helium 6. Through these procedures, when a magnetic field is formed by feeding a current in the superconductive coil 6, the line of magnetic force expanding outside the superconductive coil 8 can be shielded (absorbed) by the Meissner effect of superconductive wires 17. |
