Feasible Applications of Bulk HTS Magnets and Magnetic Field-Capturing Characteristics in Their Activation Processes

Feasible applications in the industrial regions for the bulk high-temperature superconducting (HTS) magnets have been investigated in two categories of the strong magnetic field generators and the magnetic levitation devices by active and passive field trapping, respectively. When we adopt the system to the active field generators, magnetization procedures are necessary. The authors have studied the field-capturing abilities of the HTS bulk magnets on two ways of the activation procedure and the material designing. In the former, we clarified the magnetic flux behavior that invades into bulk magnets, and that the invading flux motion is affected by the previously existing flux distribution. Therefore, the magnetic flux can be accumulated with successive magnetic fields applications with descending heat generation in order. In the latter, the selective magnetic field invasion was observed between wide- and narrow-growth sector regions. Since the bulk magnets with steep magnetic field distributions deform their own field distribution shape to be uniform by the shielding effect when the ferromagnetic plate was attached on the magnetic pole, we have succeeded in obtaining the uniform magnetic field of several-hundred parts per million in the space between the magnetic poles.