| 摘要 |
PURPOSE:To easily control a generated magnetic field by providing a composite magnet composed of a core made of an R-Ba-Cu-O bulk superconducting material manufactured by a melting method and a normal conducting or superconducting coil surrounding the core. CONSTITUTION:A superconducting bulk body 1 is obtained from an R-Ba-Cu-O superconducting material, with the R being composed of one or more tare-earth elements selected from among Y, Sm, Eu, Gd, Dy, Ho, and Er by using a melting method. A composite magnet is formed by winding a superconducting copper coil 2a which can make an electric current of 10A in maximum to flow around the bulk body 1 by 100 turns. When an electric current of 5A is made to flow to the coil 2a, a 1-kG magnetic field is generated at the central part of the bulk body 1 and, when an electric current is made to flow in the opposite direction, the magnetic field of the bulk body 1 gradually becomes weaker and the outer periphery of the magnetic field becomes zero at 5A. Therefore, the magnetic field of the bulk body 1 can be changed. |
