Cryogenic vessel for a superconducting apparatus

摘要

A cryogenic vessel for a superconducting apparatus has an inner vessel 3 which houses a cryogenic medium e.g. He and a winding of a superconducting apparatus. The inner vessel is surrounded by a vacuum insulating vessel 4 which thermally insulates the inner vessel. A connecting pipe 7 connects the inside of the inner vessel with the outside of the vacuum insulating vessel. A cylindrical dividing pipe 21 surrounds the connecting pipe with a radial clearance therebetween, extends into the inner vessel and is connected between the inner end of the connecting pipe and the inner vessel. A gas flow passageway is formed between the inner end and the outer end of the connecting pipe, the passageway bordering on the inner or outer surface of the connecting pipe. During normal operation, gas which is formed by the vaporization of a cryogenic medium contained inside the inner vessel continually passes along the passageway, absorbing heat from the connecting pipe and reducing the amount of heat which penetrates into the inner vessel by conduction along the connecting pipe. A wiring support pipe for the power supply leads is a single, rigid pipe 70 which has one of its ends connected to the inner vessel or the vacuum insulating vessel by a flexible tube 71 which absorbs thermal shrinkage. Since the wiring support pipe is a single, rigid pipe, it undergoes thermal shrinkage by about the same amount as the power supply leads which it supports, and thermal stresses do not develop in the power supply leads.