Further developments in NbTi superconductors with artificial pinning centers

Artificial pinning centers (APC) have been successfully incorporated in multifilamentary NbTi based superconductors. using pure niobium as the pinning material and applying state-of-the-art processing technology, we have developed conductors which exhibit record low-field current densities. Two volume fractions of Nb have been investigated. One of the objectives of the present development effort is the feasibility study of billet scale-up from earlier work. A J3(3T) of ∼7500 A/mm2, which is twice that of the present MRI conductors, and a Jc(5T) of ∼3400 A/mm2, have been achieved in samples. The results of this ongoing effort, in terms of conductor configuration, microstructure, critical current density, and pinning force, are presented in this paper. Appropriate comparisons with past performances are made