| 摘要 |
PURPOSE:To enable superconductive condition to be kept even if a part of a superconductive coil is exposed from liquid helium by a method wherein an electric lead connecting the superconductive coil with exciting current source is connected thermally with the liquid helium by an electric lead cooling device. CONSTITUTION:A superconductive coil 2 cooled by liquid helium 3 inside a cryogenic container 1 is connected with exciting current source 4 outside the container 1 by an electric lead 5. A connecting section 11a of an electric lead cooling device 11 is wound around the electric lead 5 and a heat exchange plate 11b is extended to the position under lower edge of the superconductive coil 2. Just then, since heat intrusion from the electric lead 5 gets to the superconductive coil 2 and breakage of superconductivity is not generated, then superconductive condition can be kept even though a part of the superconductive coil 2 is exposed above liquid level of the liquid helium 3. |
