Long Length Welded NbTi CIC Superconducting Cable for Accelerators Applications

Hyper Tech proposes to develop a long-length structured cable for use in superconducting accelera- tor magnets. The Medium-energy Electron-Ion Collider (MEIC) is a proposed colliding beam facility in which polarized beams of ions and electrons would be collided at energies up to ~100 GeV/u for ions and 20 GeV for electrons. The arc lattice for its ion ring would contain a total of 128 half-cells, and each half- cell contains two 3 T superferric dipoles. The best option for the MEIC Ion Ring dipole is a superferric
block-coil dipole in which the windings are fabricated using NbTi/Cu cable-in-conduit (CIC) conductor. Accelerator Technology Corp. (ATC) has collaborated with the Accelerator Research Lab (ARL) at Texas A&M University and has developed and patented a CIC cable for this purpose. It is made by ca- bling strands of NbTi wire onto a perforated spring tube, inserting the cable into a sheath tube, and draw- ing the sheath tube onto the cable to compress the strands against the spring tube and immobilize them. The challenge for using this CIC approach is that continuous cable lengths of ~300 m will be required for each dipole. Pulling the cable through such a long sheath is a challenge, and the cable would be more manufacturable if it were possible to form the sheath tube onto the cable in a continuous process. Hyper Tech proposes to adapt its patented Continuous Tube Forming method (CTFF) to form and weld the sheath tube directly onto the ATC/ARL cable as a continuous process. Hyper Tech has used its CTFF successfully to make continuous-length multifilament superconductor wire containing MgB2 subel- ements, and that wire is now a commercial product. We are confident that we can adapt the CTFF pro- cess to make long-length NbTi CIC cable for the MEIC requirements and to create a new commercial product. A key aspect of the proposed development will be developing the weld process so that the cable is helium leak-tight. Helium leak tight welds was not required for Hyper Tech’s present uses of the CTFF process, and developing and demonstrating the He-leak-tight seam will be a primary goal of the Phase 1 effort. A follow-on Phase 2 effort would have the goal of producing 300 m lengths of CTFF-CIC cable that meet the requirements for the MEIC project. Hyper Tech is developing a long-length superconducting NbTi CIC cable that can improve the performance/cost for a new DOE research and medical facilities for iso- tope production.

Commercial Applications and Other Benefits: The development of long length NbTi CIC cable has major potential benefit for a number of acceler- ator magnet requirements beyond its use in MEIC. Hyper Tech has a major market opportunity for NbTi CIC cable for several practical applications that are importance in society and industry for High Energy Physic facilities, MRI, and fusion applications.