| 摘要 |
PURPOSE:To eliminate heat energy, generated in the mounting shaft of a coil upon transition, fundamentally and protect a superconductive conductor thermal ly, by a method wherein the mounting shaft, supporting and accommodating the field coil, is constituted of a material such as ceramics, fiber reinforced plastics or the like which is non-magnetic and provided with a small electric conductivity. CONSTITUTION:Liquid helium, having a temperature of the degree of 4K, is employed as a liquid refrigerant 1, the superconductive body of a field coil 2 is constituted of NbTi, Nb3Sn or the like and a coil mounting shaft 3 is constituted of a non-metallic, non-magnetic, highly strong and low electroconductive material such as ceramics, fiber reinforced plastics or the like. According to this structure, eddy current loss is generated in only a torque tube 4 in the vicinity of the superconductive field coil 2 when the periodical change of a flux density occurs upon accident. The loss, generated here, is interfered in propagating to the refrigerant 1 immediately by a heat insulating tube 10 or the like of Teflon or the like between the torque tube 4 and the superconductive coil 2 and heat due to the loss is transferred gradually, there fore, the affection of the heat to the superconductive field coil 2 is small. |
