Development of an 8-T Conduction—Cooled Superconducting Magnet With 300-mm Warm Bore for Material Processing Application

A wide-bore conduction-cooled superconducting magnet was designed, fabricated, and tested for material processing applications. The superconducting magnet has a large clear warm bore of Ø300 mm, the maximum center field of 8 T, the homogeneity of 97% in homogeneous regions of Ø300 mm × 50 mm. The magnet is composed of three coaxial coils made with NbTi low-temperature superconducting wires. All the coils were connected in series and will be operated with a current of 82.2 A with a high level of stored energy, i.e., about 2.13 MJ. A passive protection based on a subdivided scheme is adopted to protect the magnet from damage caused by a quench. Two two-stage GM cryocoolers with the second-stage cooling power of 1.5 W is used to cool the superconducting magnet from room temperature to 4.2 K. In this paper, magnetic design, stress and strain analysis, quench protection, fabrication, and test are presented.