• P. Ferracin, S. Caspi, H. Felice, D. Leitner, C.M. Lyneis, S. Prestemon, G.L. Sabbi, D.S. Todd
  LBNL, Berkeley, California

Third generation Electron Cyclotron Resonance (ECR) ion sources operate at rf frequencies between 20 and 30 GHz and employ NbTi superconducting magnets with a conductor peak field of 6-7 T. A significant gain in performance can be achieved by replacing NbTi with Nb3Sn, allowing solenoids and sextupole coils to reach a field of 15 T in the windings. In this paper we describe the design of a Nb3Sn superconducting magnet for a fourth generation ECR source operating at a rf frequency of 56 GHz. The magnet design features a configuration with an internal sextupole magnet surrounded by three solenoids. A finite element magnetic model has been used to investigate conductor peak fields and the operational margins. Results of the numerical analysis are presented and discussed.