Magnetic Shielding by Superposition of Hybrid Ferromagnetic Cylinder over a YBCO Thick-Film Cylinder

Abstract

In magnetic shielding using high critical temperature (high-T_c) superconducting thick-films, it is, in general, difficult to fabricate very high-J_c (critical current density) vessels. The practical difficulty of realizing magnetic shielding using high-T_c superconductors requires to improve the magnetic shielding effect on the high-T_c superconducting vessels. The maximum shielded mag- netic flux density (B_s) is shown to be improved by the superposition of a hybrid ferromagnetic cylinders over a Y-Ba-Cu-O (YBCO) thick-film cylinder; termed the hybrid-type superimposed cylinder. The value of B_s for the hybrid-type superimposed cylinder was obtained to be about 160 times larger than that for the single-YBCO thick-film cylinder.