Design, Fabrication, and Performance Tests of a HTS Superconducting Dipole Magnet

The use of HTS (high-temperature superconductor) coils for accelerator magnets decreases significantly the power consumption and operating cost. Therefore, a preliminary study was launched and a prototype of a dipole magnet with HTS coils has been designed and fabricated by NSRRC and HTS-110 Ltd. Although 2G YBCO wire is expected to be used in future HTS applications, it currently requires more joints to form the completed coils. For this reason, we chose 1G BSCCO wires for the HTS coils. Two single-stage pulse-tube refrigerators with one compressor serve to cool the HTS coils of the magnet, but we shall use LN₂ to replace the pulse-tube refrigerators in the future. The HTS magnet is designed to provide a stable field of strength 1.19 T with field homogeneity better than 1.5 × 10^-4 in the range of the transverse -20 ≤ x ≤ 20 mm direction when it operates at 50 K with a current of 110 A. To compare with the field features of copper-coil dipole magnets, a Hall-probe measurement system was used to measure the detailed magnetic field and B-I characteristics of the HTS dipole magnet at NSRRC.