Feasibility of a 5 T magnet by using Bi-2223/Ag tape at 30 K

The feasibility of a 5 T magnet by using Bi-2223/Ag tapes at 30 K has been investigated. Preliminary computation demonstrates that the target is attai nable by assembling 20 double pancakes manufactured by co-winding two Bi-22 23/Ag tapes having overall cross-section of 0.25 x 3.5 mm(2) and 25% fill f actor, being the expected operating current about 200 A. The pancakes locat ed at the edges are the most critical because the component of the magnetic field orthogonal to the tape surface is large enough to strongly depress J (c). To overcome this problem the edge pancakes could be fabricated by usin g Bi-2223/Ag tapes with new concept design (e.g. with oriented filaments).