| 摘要 |
PROBLEM TO BE SOLVED: To provide a spherical second-class superconductor without having a magnetic flux pinning center, and to provide its manufacturing method. SOLUTION: This manufacturing method of this spherical superconductor includes the following processes: a superconductor material is formed into a bulk shape, set in a static suspension device, suspended by applying a voltage between an upper electrode 1 and a lower electrode 2 while charging it by irradiating it with an ultraviolet ray 5, and melted by irradiating it with a heating laser beam 4; and next, the molten superconductor is solidified from an overcooled state in a suspended form; and the solidified superconductor is cooled in the suspended form. In the case of a spherical superconductor formed of Nb, the superconductor material may be Nb material powder having a purity above 99.99%, which is formed into a bulk shape by an arc melting method. The superconductor material is melted by irradiating it with Nd:YAG laser, negatively charged by irradiating it with an ultraviolet ray, and suspended by a static suspension method for suspending it by an electrostatic field. The temperature in the overcooled state reaches 1,777-2,377°C. COPYRIGHT: (C)2004,JPO
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