Method and apparatus for cooling superconductor

An apparatus for cooling, by a refrigerant, a superconductor which is placed in the refrigerant, comprising:

• a refrigerating apparatus or refrigerating system for cooling the refrigerant to or below a freezing point which is given by the refrigerant having a stationary state in the cooling system of the superconductor;
• means for allowing the refrigerant cooled to or below the freezing point to flow;
• means for measuring viscosity of the refrigerant;
• and
• means for modulating a fluid state of the refrigerant according to the measured viscosity.

A cooling method for a superconductor comprising the steps of:

• liquefying air or a mixture of nitrogen and oxygen by a refrigerator, wherein the refrigerator employs a refrigerating cycle for its cooling function, and the air or the mixture is cooled outside the refrigerating cycle via a cooling part placed on the refrigerating cycle;
• circulating the liquefied air or the mixture, optionally while cooling it;
• and
• cooling the superconductor by the circulated the liquefied air or the mixture.

A cooling apparatus for a superconductor comprising:

• a refrigerator employing a refrigerating cycle for its cooling function, and having, on the refrigerating cycle, a cryogenic part which exhibits a temperature lower than a liquefying temperature of air or a mixture of nitrogen and oxygen;
• a vessel housing therein at least a part of the cryogenic part;
• a first piping system for discharging the liquefied air or mixture of nitrogen and oxygen stored in the vessel therefrom;
• a second piping system for directing the discharged liquefied air or the mixture to the superconductor and circulating the liquefied air or the mixture;
• and
• means placed at the second piping system for cooling the liquefied air or the mixture supplied to the superconductor, wherein
• the air or the mixture of nitrogen and oxygen in the vessel is cooled to be liquefied outside the refrigerating cycle via the cryogenic part, and
• the superconductor is cooled by the liquefied air or mixture of nitrogen and oxygen.

A cooling apparatus for a superconductor comprising:

• a refrigerator employing a refrigerating cycle for its cooling function, and having, on the refrigerating cycle, a cryogenic part exhibiting a temperature lower than a liquefying temperature of air or a mixture of nitrogen and oxygen;
• and
• a vessel which simultaneously houses therein at least a part of the cryogenic part and a superconductor to be cooled, wherein
• the vessel holds liquefied air or mixture of nitrogen and oxygen for cooling the superconductor, and convection of the liquefied air or mixture occurs in the vessel between the cryogenic part and the superconductor, or vaporization of the liquefied air or mixture and condensation of the vaporized air or mixture by the cryogenic part occur in the vessel.