| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for measuring a critical current density, which can simply and nondestructively measure the critical current density, by adopting a measurement value of repulsive force which is generated in interactions between a superconductive thin film and a permanent magnet and measured by a load sensor, on the basis of a graph (Jc-a<SB>1</SB>/d graph), representing the relation between the critical current density (Jc) and the repulsive force per thickness of the superconducting thin film (a<SB>1</SB>/d) which is previously obtained by using a magnetization characteristic method, a four-terminal method, a derivation method or the like. SOLUTION: A method, using the permanent magnet 6 for evaluating the critical current density, is used in order to nondestructively measure elongated high-quality superconducting wires. The measurement principle is that a load measurement sensor measures the repulsive force and an attractive force generated respectively, by making the permanent magnet close to and distant from a cooled superconductor 8, and the critical current density is evaluated from the loading characterization of the repulsive force in the measured results. According to this method, the thickness of a film which is made incapable of measurment by using the derivation method, can be measured, and an in-plane distribution can be measured with a high resolution by narrowing the magnetic field of the permanent magnet. COPYRIGHT: (C)2005,JPO&NCIPI
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