| 摘要 |
PURPOSE:To increase a critical conduction density while decreasing the leakage rate of a trapped magnetic flux even in a high magnetic field and thereby to enable generation of the high magnetic field by a method wherein a crystal of an oxide superconductor shaped in a flat-plate ring is stacked vertically to the face of a flat plate. CONSTITUTION:A molded body formed by molding an oxide superconductor in the shape of a cylinder, or a body obtained by sintering this molded body, is melted by a band melting method in a furnace having a temperature gradient in a direction vertical to the central axis of the cylinder. Thereby a plate-shaped crystal is precipitated vertically to the central axis and solidified under the temperature gradient, so that a structure of stacked plate-shaped crystals be formed. The structure is so formed that the plate-shaped crystal has a part of being continuous in the shape of a ring as a single crystal even when it is inclined a little to the axis of the cylinder. According to this method, the structure has characteristics that a critical conduction density is high and the leakage rate of a trapped magnetic flux is low even under a high magnetic field. |
