| 摘要 |
PURPOSE:To unnecessitate the boat of a container to be used for direct cooling, the withstand voltage design of an internal vessel and a safety valve as well as to contrive miniaturization and light-weightedness of the title magnet by improving its heat insulating property and by thinning a heat insulating layer by a method wherein a superconducting coil is held in a vacuum atmosphere, and it is cooled indirectly by the helium gas in a circulation path. CONSTITUTION:The heat insulating container of the title superconducting magnet is composed of an external case 1 only, and a thermal shielding layer 2 and the superconducting coil 3 surrounded by the layer 2 are provided in the external case 1. The refrigerant gas come out from a compressor 7 is made to flow to a circulation path 5 from a refrigerant gas feeding end part 5a, and then after cold heat has been absorbed from the returning low temperature gas by the first heat exchanger 8a and it is cooled down further to the final tempera ture at the winding part of the cooling stage 6b on the low temperature side of the refrigerator. Subsequently, the coil 3 is cooled down to the critical temper ature Tc while the gas is flowing the winding part 5c of the coil 3. |
