Applications of superconducting permanent magnets driven by static and pulsed fields

Abstract

By making full use of an excellent trapped field performance of the c-axis oriented single-domain Ag-bearing Sm123 superconductors with a diameter of 36 mm, we have developed several superconducting permanent magnet systems driven by static and pulsed fields. The Sm123 superconductor can trap a magnetic field of 2.1 at 77 K and can increase its maximum trapped field to 9 T at 25 K in the static field cooling magnetization. A Nd-Fe-B plate (50×50×5 mm³) can be magnetized to the same level as that due to the uniform static magnetization by scanning it over the Sm123 superconducting permanent magnet. The construction of a pulse field-driven face-to-face-type magnetic field generator capable of producing 1.8 T in an open space with a gap of 12 mm is also presented. We also suggest hollowed Sm123 superconductors to serve as a permanent magnet providing a uniform magnetic field exceeding 2 T over the range up to 10 mm.