The effect of additional permanent magnet configuration on the levitation force of single domain GdBCO bulk superconductor

Effects of additional permanent magnet configuration on the levitation force of a single domain GdBCO bulk superconductor have been investigated with a cylindrical permanent magnet in their coaxial configuration at liquid nitrogen temperature. The single-domain GdBCO sample is of φ20mm and 10mm in thickness; the two additional permanent magnets are of rectangular parallelepiped shape, and placed on two sides of the GdBCO bulk superconductor in different arrangement; the magnetic pole N of the cylindrical permanent magnet is directed to the GdBCO bulk superconductor in their coaxial configuration. It is found that the maximum levitation force decreases from 74.7N to 30.1N while the distance(Daps) between the additional permanent magnet and the superconductor is increased from 0mm to 20mm, if the magnetic pole N of the two additional permanent magnets horizontally point to the GdBCO bulk superconductor; the largest maximum levitation force is only 22.8N while the distance Daps is increasing from 0mm to 20mm, if the magnetic poles N of the two additional permanent magnets are antiparallel to the magnetic poles N of the cylindrical permanent magnet. The results indicate that the higher levitation force can be obtained by introducing additional permanent magnets based on scientific and reasonable design of the system, which is helpful for designing and constructing superconducting magnetic levitation systems.