Tooling Design, Coil Fabrication, and Prototype Coil Performance Verification for a 28 GHz Nb3Sn ECR Ion Source Magnet

Worldwide several superconducting electron cyclotron resonance (ECR) ion sources have been developed and in operation for heavy ion accelerators using Nb-Ti magnets. To explore the use of high-field Nb$_{3}$Sn to break the field limit of Nb-Ti for ECR magnets, state-of-the-art Nb$_{3}$Sn coil fabrication techniques and tooling design must be used to address the challenging characteristics of Nb$_{3}$Sn conductors. Earlier we reported the overall magnet design, conductor selection, and conductor characterization for building a 28 GHz superconducting ECR ion source using Nb$_{3}$Sn sextupole coils for Facility for Rare Isotope Beams (FRIB). This paper describes the progress towards fabricating prototype Nb$_{3}$Sn sextupole coil. In particular, we present tooling design, Nb$_{3}$Sn sextupole coil fabrication, and a mirror magnet for performance verification.