MgB2 SYSTEM SUPERCONDUCTIVITY WIRE FOR LIQUID HYDROGEN LIQUID LEVEL SENSOR, LIQUID HYDROGEN LIQUID LEVEL SENSOR, AND LEVEL METER FOR LIQUID HYDROGEN

摘要

PROBLEM TO BE SOLVED: To provide an MgBsystem superconductivity wire for liquid hydrogen liquid level sensor capable of maintaining that a non-immersion portion is not a superconductive state even if the non-immersion portion of the MgBsystem superconductivity wire for liquid hydrogen liquid level sensors is not heated.SOLUTION: A wire for liquid hydrogen liquid level sensors made of MgBsystem superconductivity material containing Mg, B and Al is used. When electric resistance is substantially zero, critical temperature is 20 to 25K. A transition width which is a difference between a temperature when electric resistance starts to fall for zero and the critical temperature is 5K or less.