Bending of Bi(2223) - Ag tapes at 77 and 300 K

An experimental study of Bi(2223) - Ag tapes undergoing bending and straightening at 300 and 77 K has been performed. The special test equipment allows us to measure changes of the critical current in a short element of the tape during continual decreasing or increasing of the bending diameter at both temperatures mentioned above. Comparison of 300 and 77 K results shows the effect of the Ag sheath strength on the bending sensitivity of Bi(2223) - Ag composite tape. Remarkable lowering of critical current degradation by bending at 77 K was observed. This offers the possibility of winding small-diameter coils with Bi(2223) - Ag tape pre-cooled by liquid nitrogen.