Modular High Field Quadrupole Design for Electron–Ion Collider

The proposed electron-ion collider (EIC) needs high-gradient, large-aperture quadrupole magnets in the interaction region (IR). This paper presents the work under a Small Business Innovation Research Phase I grant to Particle Beam Lasers, Inc., and Brookhaven National Laboratory (BNL) to develop a novel modular design for EIC quadrupoles based on racetrack coils, which need no expensive tooling to build. It also enables the same coils to be used in Nb3Sn magnets of a range of apertures. Such a modular program may greatly facilitate R&D and reduce its costs, which often dominate the total cost of magnets that are one-of-a-kind or produced in limited numbers. For the EIC IR, the same coils are used in four R&D quadrupoles: one Nb3Sn quadrupole as proposed for the BNL eRHIC and three Nb3Sn quadrupoles as proposed by Jefferson Laboratory for JLEIC. This paper will present the basic magnetic and mechanical design of the several IR quadrupoles for the proposed EIC.