| 摘要 |
PURPOSE:To decrease the amount of the heat intrusion by coupling the opening parts of the containers which face to each other at the upper and lower positions in a hermetically sealing manner with an insulating member being held in-between which is turned ON and OFF by moving the liquid level of the liquid metal in the inside in series. CONSTITUTION:A superconductive coil 2 is enclosed in a very low temperature container 1 and immersed in refrigerant 3. Said container is placed in a vacuum container 4 and heat is insulated by a vacuum. The heat intrusion into the superconductive coil 2 is prevented by the current lead device 5 which pierces through the very low temperature container 1 and the vacuum container 4. A heat insulating path device 11 is connected to the part between the current lead device 5 and a power source lead 7 in series. The power source lead 7 pierces through an upper container 13 of the heat insulating path device 11, and a conductor 7a which is connected to the current device 5 pierces through a lower container 14. The upper and lower containers 13 and 14 are tightened by the insulating member 15. The liquid metal 18 such as mercury is supplied or drained through a pipe 19. In this constitution, the level of the liquid metal 18 is moved up and down and the conduction is activated or cut, and the heat intrusion is decreased when the current is not conducted. |
