Development of Portable Superconducting Bulk Magnet System

A magnetic drug delivery system (MDDS) has recently been developed enabling magnetic seeded drugs to be navigated around the diseased parts of the human body. To improve the magnetic drug delivery performance, a portable superconducting bulk magnet system with strong magnetic fields has also been developed. This magnet system primarily consists of small bulk high-temperature superconductors and a compact Stirling-cycle cryocooler. The materials used in the high-temperature superconductors are rare earth 123 single domain compounds (GdBaCuO). The main body of the magnet is 9.5 kg and 740 mm in length. In this study, a bulk magnet was successfully activated using field-cooling magnetization under a superconducting solenoid magnet. The magnetic flux densities at the surface of the vacuum chambers that contain the bulk magnets reached 5.07 T and 6.76 T under the static fields of 6 T and 10 T, respectively. We clarified that the magnetic gradient was approximately 10 T/m at a position 50 mm from the surface of the vacuum chambers. This operating bulk magnet system is portable and can be easily transported via car over long distances.