Compact Superconducting Dipoles and Quadrupoles for Final Focus in an Electron Ion Collider

Hyper Tech proposes to develop a new technology for the high-performance superconducting mag- nets that are required for final focus in an electron-ion collider. The Electron-Ion Collider (EIC) is a pro- posed colliding beam facility in which polarized beams of ions and electrons would be to study the spin structure of nuclear matter. Final-focus (FF) magnets are required to focus the beams as they approach the collision point to maximize the rate of collisions. These magnets are a significant design challenge for the project, because they must operate with several difficult requirements: (1) The quadrupole lenses must operate in the fringe field of the large magnetic solenoid of the detector used to study collisions. That field has the potential to saturate the magnetic properties of the FF quadrupoles; (2) The FF lenses that focus ions after collision must have high focusing strength in order to match the outgoing beam to the collider lattice, but also large aperture to pass scattered ions so that they may be studied by detector elements beyond the lenses; (3) The two beams are converging together with small separation at the locations of the FF lenses, but the lenses on one beam must produce no fields at the other beam; (4) The FF lenses must operate in an environment of intense radiation damage and heat load from beam losses into the superconducting windings. Hyper Tech has teamed with the Accelerator Research Lab (ARL) at Texas A&M University and Accelerator Technology Corp. (ATC) to develop a cable-in-conduit quadrupole technology that can satis- fy all of the EIC FF requirements. The windings use a small diameter superconducting cable-in-conduit (CIC) design, in which the cryogenics is integrated within the cable itself so that it can operate stably in the highest radiation loads. The magnet structure uses a steel flux return, with an active ‘stealth’ shield that excludes the fields of the detector solenoid from penetrating the flux return. For elements that are closest to the other beam tube it also includes an active flux-return booster that cancels fringe fields that would otherwise be produced upon the other beam. The small diameter CIC cables will be developed using MgB2 and Nb3Sn wires that require heat treatment after winding in to coil form. The Phase 1 effort will focus upon fabricating and testing CIC cable using MgB2 and Nb3Sn super- conducting strand and preparing optimized conceptual designs for the family of FF magnets. In a follow- on Phase 2 effort we would fabricate long-length MgB2 and Nb3Sn CIC cables and fabricate a first model quadrupole for a specific example element in the FF designs for the JLab and BNL designs for the EIC. Commercial Applications and other benefits The commercial applications are small diameter cable-in-conduit magnets for high energy physics and nuclear physics accelerators, MRI, Fault Current Limiters, Motors, Generators, and SMES