Construction of a strong magnetic field generator with use of melt-processed bulk superconductors

A superconducting permanent magnet system capable of generating strong magnetic fields has been constructed by using melt-processed bulk superconductors as trapped field magnets. The trapped field in the open space between two magnetic poles that are set face to face has reached 3.15 T when magnetized by a pulsed-field magnetization (PFM) technique. That was operated at 30 K attained by GM-cycle refrigerators. The performance exceeds that of conventional rare earth magnets or large scale electromagnets by far. It was found that the iteratively magnetizing pulsed field operation with reducing amplitude (IMRA) method is very effective in magnetizing the bulk superconductors. The magnet system can be used as a high field generator in various applications.