Preparation of high performance Nb3Sn tape by a high tape rate CVD process

We have investigated some growth characteristics of Nb3Sn layer in continuous CVD process. A new CVD technique has been developed by the authors for preparing commercial Nb3Sn tapes (2.5 mm in width, 8-10 um thick layered films per side) so as to increase the tape productivity to 50-100 m/hn. In this case, the Ic´s and Jc´s of short samples have reached 600 780A and 1.4-1.6×10⁶A/cm²at 4.2 K and 4-5 T, respectively, and single long tapes of about 1000 m in length, wound into 18 mm I.D. and 100 mm high solenoids, have generated a ∼10 T magnetic field as they carry a current of 150-180 A at 4.2 K; the corresponding values of Jc(Nb3Sn) and Jc(conductor) have reached 3-5×10⁵A/cm²and 4-5×10⁴A/cm², respectively.