高磁気力小型マグネットの検討  [in Japanese] Design of a Compact Magnet for a High Magnetic Force  [in Japanese]

The condition for enlarging the product of the magnetic field and its gradient, B・dB/dz, of a ready-made small superconducting magnet was investigated by computer simulation. The calculation assumed the use of a superconducting magnet with 100-mm-diameter room-temperature bore and capable of producing a 10T magnetic field at the center. The value of B・dB/dz seems to be amplified when an iron ring or inner coil is inserted into the bore of a small superconducting magnet. Indedd, when an iron ring with an inner diameter of 10mm or a pair of inner coils with an inner diameter of 40mm is inserted, the value of B・dB/dz increased sufficiently to satisfy the condition for water levitation. These results suggest the possibility of using an ordinary smal superconducting magnet to levitate diamagnetic materials.