ADVANCED CONDUCTOR TECHNOLOGIES LLC — Department of Energy STTR Phase II: 26b

Description

"The next generation of very high field accelerator magnets (20 T or more) are expected to be made with high-temperature superconductors (HTS) along with conventional low-temperature superconductors (LTS) to reduce cost. The operation and protection of these magnets becomes very challenging particularly if the HTS coils are made with the tapes and operate at a much lower current than the LTS coils. Accelerator magnets must also satisfy the stringent field quality requirements, which is a significant challenge for magnets made with HTS tapes. We propose to develop very high field hybrid accelerator magnet technology using HTS coils made with high current CORC® cables operating in series with the LTS coils made with Rutherford cables. The coils made with the partially transposed CORC® cables offer higher current operation and better field quality than the coils made with HTS tapes. The CORC® cables have matured into a high performance magnet cable. The common coil design, a conductor-friendly design with large bend radii, enables a rapid transition of high current density CORC® cables into 2-in-1 collider dipoles. During Phase I of the program, we’ve increased the current density in CORC® cables to 400 A/mm2 at 4.2 K and 20 T. Initial hybrid Common Coil magnets have been designed, showing that the current CORC® cable performance is more than sufficient to reach a total field of 16 T with an existing 10 T LTS outsert. During Phase II, we will design, manufacture, and test a fullsize hybrid Common Coil magnet with a CORC® insert coil that would generate at least 14 T. Conceptual designs for a 20 T hybrid magnet will also be developed, taking all factors important for accelerator magnets into account, such as field quality and quench protection. Commercial Applications and Other Benefits High field magnets wound from high-temperature superconducting magnet cables will enable some of the next generation of high-energy physics magnets, proton cancer treatment facilities, practical fusion magnets, and scientific magnets. These magnets will also benefit superconducting magnetic energy storage systems for use in the power grid and for application within the Department of Defense. "