Abstract: This invention is a superconductor having a generally substoichiometric oxygen, nickel oxide insulation between superconduction strands. The superconductor is to have an operating temperature below 250 degrees kelvin, and has multiple superconductors, with a cladding of nickel on the strands, and an adherent coating of nickel oxide formed on the outer surface of the cladding. The nickel oxide has stoichiometric or less than stoichiometric oxygen (but not greater than stoichiometric oxygen) to be electrically insulating at the operating temperature of the superconductor. Thus high thermal conductivity strand insulation capable of withstanding strand to strand voltages of greater than 50 volts is provided to substantially eliminate coupling currents between the strands, and nickel oxide having areas of semiconducting due to containing more than stoichiometric oxygen is avoided.

Abstract: A cryogenic liquid coolant transfer device enhances flow of a liquified gas in the inboard direction by the incorporation of a threaded insert in the rotating inlet pipe of a superconducting rotor. The threads of the device also facilitate the reverse flow of liquid helium back into a stationary supply tube during fault conditions. The objective of the insert, during both normal and abnormal conditions, is to inhibit the flow of liquid coolant into the clearance gap that exists between rotating and stationary parts of the liquified gas transfer system.