Low field magnets with high temperature superconductors for an upgrade of CESR

An upgrade to the CESR electron-positron storage ring is being considered in which the single ring machine is replaced with two rings capable of storing high currents to provide high luminosity symmetric electron-positron collisions. This paper considers the implementation of the two rings using dual bore quadrupoles fabricated with high temperature superconductors (HTS). The use of HTS provides the required high current density needed to achieve the small (81 mm) inter-beam spacing, with a simpler and more efficient cryogenic system than would be required with conventional low-temperature superconductors. Concepts for the quadrupole magnetic and cryostat design are discussed. A concept for dipole magnets using Nb₃Sn, integrated with a warm beam tube vacuum system, is also discussed