Effect of Anisotropic Magnetization on the Rotational Loss in YBCO Bulk Superconductor

Eddy loss caused by the ununiformed magnetizing field of high temperature superconductor (HTS), which is field cooled by a permanent magnet (PM), is one of the main losses in the rotating superconducting suspension. Due to the incompletely symmetrical magnetic field of PM and the anisotropy magnetization in HTS, there should be an optimal field cooling position in which the magnetizing field should have the best uniformity. To find out the perfect position, the distributions of radial magnetizing field of HTS are compared under different field cooling heights (FCH), eccentric distances and in-plane angles of the PM. Meanwhile, the magnetic field distribution of a cylindrical PM is measured to investigate the anisotropic magnetization of the HTS. The results of tests present that there is a magnetic moment in horizontal direction of the PM. Set this magnetic moment direction as the representative of the position of PM. There is a great influence on the uniformity of magnetizing field by the eccentric distance. Under the same eccentric distance, there is little effect on the priority in-plane angle with the changing of FCH. The priority in-plane angle is determined by the magnetizing anisotropy in ab-plane.