Magnetic shielding effects by the superposition of a six-layered ferromagnetic cylinder over a BPSCCO cylinder

The maximum shielded magnetic flux density ([B.sub.s]) was shown to be improved by the superposition of a six-layered ferromagnetic cylinder over a Bi-Pb-Sr-Ca-Cu-O (BPSCCO) cylinder; termed the six-layered superimposed cylinder. The values of [B.sub.s] for the six-layered superimposed cylinder were found to be about 100 times greater than that of a single-BPSCCO cylinder. The values of [B.sub.s] were analyzed by using several different models. It was found that the experimental values orbs agree well with theoretical values. The results confirm that an important criterion was determined for the design of an effective shield for large chambers.