| 摘要 |
PURPOSE:To reduce invasion heat from a current supply lead body to a liquid helium container, by constituting a space between a liquid nitrogen container of a current supply lead body and a terminal on the superconducting coil side of a high temperature superconductive material. CONSTITUTION:Almost at the intermediate part of a gas tube 5 provided from the normal temperature side terminal 7 to a superconducting coil side terminal 8, a liquid nitrogen container 12, which houses liquid nitrogen 10 and through which a current supply lead 11 runs, is arranged. Further, this current supply lead 11 is so constituted respectively that a copper material is used for the lead part 11a from its normal temperature terminal 7 to a liquid nitrogen container, while a high-temperature superconducting material of a ceramic base showing a superconductive state above a liquid nitrogen temperature is used for the lead part 11b from the liquid nitrogen container 12 to a superconducting coil side terminal 8, and both of them are connected in the intermediate connection part 13 inside the liquid nitrogen container 12. Since the lead part 11b consisting of the high-temperature superconducting material is always held in the superconductive state so as to generate no Joule heat, the invasion heat from a current supply lead body to a liquid helium container is extremely little. |
