Multifilamentary Round Wires of REBCO Coated Conductors for High Field Accelerators

There is substantial interest in the upgrading of the existing High Energy Physics accelerators including the Large Hadron Collider in CERN, Switzerland to higher energy levels so as to probe deeper into the subatomic scale and unlock the mysteries of the Universe. Such upgrades to higher energy levels would require use of High Temperature Superconductor (HTS) magnets which can generate magnetic fields levels of 20 T and beyond. However, in order to use HTS tapes in ultrahigh field accelerator magnets, challenges with flat geometry and wide profiles, anisotropic properties and losses during magnet ramping have to be overcome. Recently, our Research Institution partner, the University of Houston developed an innovative approach to fabricate round wires of RE-Ba-Cu-O (REBCO, RE=rare earth) HTS tapes with diameters of 1.2 to 1.6 mm. Additionally, multifilamentary REBCO conductors with filament widths 90 – 200 μm have also been demonstrated. However, numerous challenges remain in combining and scaling up these technologies to long lengths of round multifilamentary REBCO wires. In the proposed program, AMPeers LLC will work with the University of Houston to further develop and scale up technologies to fabricate high performance, ultra-small diameter, multifilamentary wires of REBCO tapes. Electromagnetic and mechanical properties of these wires will be fully tested and guide the development and scale up of this innovative technology. Achievement of round, multifilamentary, ultra-small diameter REBCO wires in long lengths in the proposed program will serve a market need that has been unmet for nearly 30 years ever since the discovery of HTS materials. In addition to meeting the needs of High Energy Accelerators that would operate at 20 T and beyond for High Energy Physics, the new technology would be highly impactful in the ommercial market for accelerators which includes proton beam therapy in medicine, ion implantation for digital electronics, for safer use of nuclear energy, treatment of water and flue gases, pharmaceutical drug development and nuclear forensics and cargo screening for security. Additionally, the round REBCO wire technology developed in this program can enable commercialization of HTS technology in power applications such as generators, motors and transformers. Key Words – Superconductor wire, Multifilamentary wire, Coated conductor, Accelerator magnet