摘要 |
A cold insulation vessel comprises an inner chamber in which cryogen is enclosed, an outer chamber to enclose this inner chamber and a shield member against heat radiation which is provided between the inner chamber and the outer chamber. This vessel is provided to hold a superconducting coil which is enclosed in the inner chamber at a very low temperature. A power lead is provided to supply an exciting current to this superconducting coil. A recondenser is provided to recondense the evaporated gas of the cryogen in the inner chamber. The small refrigerator means has a plurality of refrigeration stages which are directly coupled to the power lead and the recondenser. |