Method for detecting non-superconducting transition of superconducting wire

摘要

A method for detecting a non-superconducting transition of a superconducting wire including a substrate, a superconducting layer having a critical temperature of 77 K or more, and a metal stabilization layer includes, adhesively attaching an optical fiber where a plurality of fiber Bragg gratings are formed in a core along a longitudinal direction thereof to the superconducting wire; measuring in advance a Bragg wavelength shift of the fiber Bragg gratings for a temperature variation of the superconducting wire, and determining a relational expression based on the shift for a temperature calculation of the superconducting wire; determining temperature variations of the fiber Bragg gratings before and after the non-superconducting transition of the superconducting wire using the relational expression; and calculating a propagation rate of the non-superconducting transition based on both a time difference of temperature increases of the fiber Bragg gratings, and an interval between each of the fiber Bragg gratings.

主权项

1. A method for detecting a non-superconducting transition of a superconducting wire comprising a substrate, a superconducting layer that has a critical temperature of 77 K or more, and a metal stabilization layer, the method comprising:
adhesively attaching an optical fiber in which a plurality of fiber Bragg gratings are formed in a core along a longitudinal direction thereof to the superconducting wire; concentrically winding the superconducting wire adhesively attached with the optical fiber in which the fiber Bragg gratings are formed; fixing the wound superconducting wire in a coil shape; after the fixing, measuring in advance a Bragg wavelength shift of the fiber Bragg gratings with respect to a temperature variation of the superconducting wire, and determining a relational expression based on the Bragg wavelength shift for a temperature calculation of the superconducting wire; measuring the temperature variation of the fiber Bragg gratings continuously from before to after the non-superconducting transition occurs in the superconducting wire; determining temperature variations of the plurality of fiber Bragg gratings before and after the non-superconducting transition of the superconducting wire using the relational expression; and calculating a propagation rate of the non-superconducting transition based on both a time difference of temperature increases of the plurality of fiber Bragg gratings, and an interval between each of the fiber Bragg gratings.