High count restacks Nb3Sn using subelements with over 3000 A/mm2 non-Cu Jc at 12T and 4.2K

Nb3Sn superconducting strands, used in magnets for high energy physics experiments, need to have smaller deft to be stable at lower fields. This means that the strands must be produced with a higher subelement restack count without wire breakage. This project will demonstrate higher subelement restack counts using subelements that have produced non-copper Jc¿s in the 3400 A/mm2 range at 12 T, and greater than 1800 A/mm2 at 15T when restacked with 61 sub elements. Phase I will fabricate strands that have 91, 127, and 217 sub elements in the restack. The strands will be characterized for current density, AC losses, and Relative Resistance Ratio of the strands. Commercial Applications and other Benefits as described by the awardee: The largest market for Nb3Sn is currently for accelerator and fusion magnets. For example, tons of strands are needed for the ITER project. Other commercial applications include high field MRI and NMR systems, proton radiation for cancer treatment, superconducting magnetic energy storage, and high field magnetic separation.