Development of Bi-2212 Rutherford cable

An 80 meter long Rutherford cable was fabricated with 20 strands of 0.8 mm diameter Bi-2212 wire. The conductor utilized in this cable was a double stack design (7 × 61) comprising 427 filaments. The critical current (Ic) of the cable was measured at liquid helium in applied magnetic field up to 4T. The Ic results of the cable show no degradation when normalized to the strand. The cable was sectioned into four 17-meter lengths and one 10-meter piece. These sections were heat treated and the ends cut and tested. The average Ic of all cable pieces tested was 2990 A ± 10% in self field. The bending strain of Rutherford cables with a ceramic coated Ni-alloy core showed little or no degradation up to 6%. In contrast, cables manufactured without a Ni-alloy core showed critical bending strains of about 2%.