Development of a 20 T class superconducting magnet with large bore

A 20 T class superconducting magnet has been constructed at the National Research Institute for Metals in Japan. The two outermost of the four coils have been operated at 4.2 K. Before operating all coils at 1.8 K, in saturated superfluid helium, breakdown voltages within the coils were measured. With an inner coil of preliminary design, the system should generate 20.4 T in a 44 mm free bore.<
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