Critical current measurements on large conductors of niobium-titanium/copper cable embedded in an aluminum stabilizer

Insertion of a flat, Rutherford type cable of NbTi/Cu composite strands into a rectangular profile of high purity aluminum is an established method of superconductor fabrication for certain applications. Although this processing scheme has numerous advantages it produces a composite material whose properties are difficult to predict with precision. The BABAR detector magnet being tested at the Stanford Linear Accelerator Center, uses high-purity aluminum stabilized superconducting cable. The performance of the superconductor is dependent on the quality of the fabrication of the composite conductor. Here we present measurements of the critical transport current of BABAR production grade conductors up to 10 kA, and at fields up to 10 T. Data are related to production variables, compared to estimates from simple models, and evaluated with respect to design specifications.