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

We have investigated some growth characteristics of Nb
3
Sn layer in continuous CVD process. A new CVD technique has been developed by the authors for preparing commercial Nb
3
Sn 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 I
c
's and J
c
's of short samples have reached 600 780A and 1.4-1.6×10
⁶
A/cm
²
at 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 J
c
(Nb
3
Sn) and J
c
(conductor) have reached 3-5×10
⁵
A/cm
²
and 4-5×10
⁴
A/cm
²
, respectively.