| 摘要 |
PURPOSE:To improve the mean current density by using a coil-shaped superconductive wire material and a sintered film of fine particles of inorganic oxides covering the surface of the coil-shaped superconductive wire material. CONSTITUTION:A bismuth-based oxide superconductive body is formed to a cylindrical pellet, this is inserted in a silver pipe and sealed at both the ends, wire drawing process is performed and a silver sheath wire material is made. Then, magnesium acetate is dissolved in ion exchange water, it is agitated and heated while adding acetic acid for gelatinization, and an acid catalyst ion exchange water are added for turning magnesium hydroxide into soil suspension. Then, the silver sheath wire material is immersed into the soil suspension, and a magnesium hydroxide layer is given to the surface of the silver sheath wire material and heat-treated in the atmosphere. Then, this is wound around a winding frame made of alumina, a required high temperature heat treatment is performed in the atmosphere, then the surface of this superconductive coil is covered with a sintered film of the fine particles of magnesium oxide about 1mum thick. By doing this, the mean current density of the whole of coil can be improved. |
