Patent ID: 7989702

Claim:
A sealing-end structure for a superconducting cable, the sealing-end structure comprising: (a) an end portion of a superconducting cable; (b) a bushing through which electric power is outputted and inputted between a normal-temperature side and a cryogenic-temperature side, at which the end portion of the superconducting cable is placed; (c) a coolant vessel that: (c1) is placed at the cryogenic-temperature side; (c2) is filled with a liquid coolant and a gaseous coolant both for cooling the bushing; and (c3) is provided with a contraction-absorbing portion for absorbing the contraction of the coolant vessel when it thermally contracts by the effect of the coolant; and (d) a narrow-clearance portion in which a clearance between an inner surface of the coolant vessel and an outer circumference of the bushing is 0.1 to 2.5 mm, wherein the narrow-clearance portion maintains the gaseous coolant at a gaseous state without pressurizing it by using a compressor, and maintains the pressure of the gaseous coolant and that of the liquid coolant in equilibrium, and a boundary between the gaseous coolant and the liquid coolant lies at a space inside the narrow-clearance portion.