| 摘要 |
PURPOSE:To prevent an oxide superconductor from being burned even if a quenching is caused in the superconductor and to make it possible to execute safely the energizing operation of a current lead by a method wherein the oxide superconductor is formed into a columnar form and a cooling groove to circulate helium gas is provided in the superconductor. CONSTITUTION:A cooling groove 25, which ranges in the longitudinal direction< of a cylindrical oxide superconductor 24 and penetrates the superconductor in the lateral direction intersecting orthogonally the longitudinal direction,(is provided in the superconductor 24 being used for a low-temperature side lead. This groove 25 is formed as a groove to range smoothly in the longitudinal direction in such a way that the straight line parts of the groove in the horizontal direction and the half-circuit arc parts arranged on the sides of the groove are arranged in order as seen from the lateral direction and is made to constitute so that cooling use He gas flows smoothly also in the longitudinal direction. Thereby, even if the superconductor 24 causes a quenching by some cause and is transferred into a normal conductive state, a local temperature rise of the superconductor 24 is inhibited, burning, which is caused by an excessive temperature rise of the superconductor 24, of the superconductor 24 is prevented from being generated and a safely operable current lead can be obtained. |
