| 摘要 |
PURPOSE:To obtain a highly reliable electric insulator even in a cooling medium of extra critical helium of high density by a construction wherein the electric insulator used in a cooling medium of such as extra critical helium has a hollow airtight inside chamber. CONSTITUTION:In an electric insulator used in a cooling medium of such as super critical helium, it is so arranged that the electric insulator has a hollow airtight inside chamber. As the space in the hollow airtight chamber 18 is cooled by a cooling medium (helium, nitrogen, etc.), the residual gas is solidified and a vacuum is maintained therein. Since the specific inductive capacity is 1, the electric field in contact with the insulator 17 is mitigated, whereas the destructive voltage is raised. In so doing, it is therefore possible to obtain a highly reliable electric insulator even in a cooling medium of such as super-critical helium processed in high density. |
