Tests and Measurements of the CESR Phase III Interaction Region Superconducting Magnets

Superconducting interaction region magnets for the CESR ring have been built by industry and tested. They will allow for higher luminosity by reducing the long range beam-beam effect at the crossing point nearest to the interaction point (IP). They also provide the necessary energy flexibility needed for charm physics operation in the future. The design of these magnets places them as close as physically possible to the IP, immersed within the 1.5 T CLEO detector solenoid field. Consequently the peak beta functions are modest, similar to arc values, and the chromaticity contribution is minimized. The magnets consist of five identical ‘units’ each with three independent sets of coils. The main quadrupole (MQ) coils are capable of gradients of up to 48.4 T/m at 1225 A. Skew quadrupole (SQ) coils are nested over the MQ coils and generate a field about 10% as strong. Dipole (D) windings occupy the outermost layer. They can produce a horizontal dipole field up to 0.13 T for vertical orbit correction.