Development and performance of a 2.9 Tesla dipole magnet using high-temperature superconducting CORC^® wires

Abstract

Although the high-temperature superconducting (HTS) REBa 2 Cu 3 O x (REBCO, RE = rare earth elements) material has a strong potential to enable dipole magnetic fields above 20 T in future circular particle colliders, the magnet and conductor technology needs to be developed. As part of an ongoing development to address this need, here we report on our CORC ® canted cos θ magnet called C2 with a target dipole field of 3 T in a 65 mm aperture. The magnet was wound with 70 m of 3.8 mm diameter CORC ® wire on machined metal mandrels. The wire had 30 commercial REBCO tapes from SuperPower Inc., each 2 mm wide with a 30 µm thick substrate. The magnet generated a peak dipole field of 2.91 T at 6.290 kA, 4.2 K. The magnet could be consistently driven into the flux-flow regime with reproducible voltage rise at an engineering current density between 400 -550 A mm −2 , allowing reliable quench detection and magnet protection. The C2 magnet represents another successful step towards the development of high-field accelerator magnet and CORC ® conductor technologies. The test results highlighted two development needs: continue improving the performance and flexibility of CORC ® wires and develop the capability to identify locations of first onset of flux-flow voltage.

Design of a Cloverleaf-Racetrack Dipole Demonstrator Magnet With Dual ReBCO Conductor

“…Another magnet to be tested at CERN in the same program is a cosine theta dipole magnet also using Roebel cable and constructed by CEA [2]. Elsewhere, canted cosine theta dipoles are made with other conductor and cable configurations, such as Bi-2212 Rutherford cable [3] and ReBCO CORC wires [4].…”

An Initial Look at the Magnetic Design of a 150 mm Aperture High-Temperature Superconducting Magnet With a Dipole Field of 8 to 10 T

“…Although the CCT design offers excellent geometric field quality as shown in Tables III and V, these field error values are computed without considering the magnet fabrication and assembly tolerance that can lead to field errors. In addition, the persistent magnetization in superconductors and dynamic effects cause additional field errors in CCT magnets [28], [66], [67]. A higher critical current in CORC R wires can exacerbate the issue but promising mitigation methods exist [10], [68].…”

A Strategic Approach to Advance Magnet Technology for Next Generation Colliders

“…In the past few years, the REBCO community has investigated different dipole magnet configurations using CORC wires and progressed towards a high-field dipole magnet technology. The three magnet configurations are common coil being developed at BNL [43], Conductor on Molded Barrels (COMB) at FNAL [44], and CCT at LBNL [45], [46], [47]. Figure 6 shows the three concepts.…”

“…Subscale models of both common coil and COMB concepts are being developed with magnets of a larger scale planned for development and testing within the next 12 months. The latest CCT magnet generated a peak dipole field of 2.9 T at 4.2 K in [47], with ongoing work to develop a magnet to 5 T at 4.2 K.…”