An Advanced Monolithic NbTi Conductor with 5 Tesla Jc of 5000 A/mm2 and Beyond for Use in Superconducting Quadrupole Magnets

73085S03-I The Heavy Ion Fusion Program has among its major objectives the development of cost effective, high gradient, superconducting quadrupole arrays for multiple beam focusing. A compact array design is required to limit the size and cost of the acceleration system. A conductor with the highest possible current density and the lowest cost would have a direct impact on fabrication of prototype quadrupole magnets. This project will develop a practical NbTi monolithic conductor, engineered with Ni/Cu artificial pinning centers, to replace and significantly outperform the Rutherford cable design. Phase I will evaluate conductors with 14%, 16%, and 18% artificially engineered Ni/Cu pins in the NbTi superconducting matrix. The conductors will be fabricated by hot extruding and processing, using a scalable manufacturing approach. The effect of the hot extrusion and processing on the ferromagnetic pins will be studied. Ferromagnetic pinning strength, pin microstructure, and bulk superconducting properties will be evaluated. Commercial Applications and Other Benefits as described by awardee: High performance, low cost, multifilament NbTi wires would expand the use of superconducting quadrupole magnets for Heavy Ion Fusion and undulators for the Synchrotron Light Source. Increased Jc also should reduce overall winding volumes, allowing the use of the well-established and less expensive NbTi winding technology rather than the more difficult, risky, and costly Nb3Sn technology.