1-G HTS Split Coil Magnet for Research Purposes

A practical split coil magnet using Bi-2223 HTS tapes has been developed and tested. The design parameter is the maximal magnetic field at the aperture of a coil. 1-G Bi-2223 tape was used for magnet's winding produced by Sumitomo Electric Industry Co. The maximum magnetic field in the magnet is determined by the dependence of 1-G tape's critical current on magnetic field normal to the HTS surface of a tape. Reduction of the normal component of the magnetic field to the HTS tape was achieved by using the iron plates. The finite element modeling has been used to design the magnet configurations. The simulation results are in good agreement with the measurement data. The maximum magnetic field at the aperture of the magnet reached 0.75 T at 77.4 K with ~1 T of maximum field on winding. The split coil is used to test anisotropy of critical currents of HTS tapes in our standard HTS wires characterization test program. The details of split coil design and magnet test results are presented.