| 摘要 |
PROBLEM TO BE SOLVED: To dip a superconducting field coil-side part of a current lead in a liquid refrigerant and cause the refrigerant to flow in the current lead stably, by forming a refrigerant bypass which allows the refrigerant to take a roundabout way outwards in the radial direction in the current lead having a refrigerant channel which runs from a liquid trap section toward outside. SOLUTION: A current lead 24, which houses a lead conductor having a superconducting field coil 5 and a slip ring 15 electrically connected in a metallic pipe, and an insulator covering the lead conductor, is provided with a U-shaped bent section 28 which is bent outwards in the radial direction, as a refrigerant bypass. Due to the existence of the bent section 28, even if the liquid level in a liquid trap section 8 goes up for some reason, liquid helium is allowed to flow into the pipe of the current lead 24 through an opening 22, thereby dipping a superconducting field coil 5-side part of the current lead 24 in the liquid helium. By this method, the liquid refrigerant can be supplied to the current lead 24 stably and the superconducting field coil 5 can be surely cooled. |
