Single bunch longitudinal measurements of the Cornell Electron-Positron Storage Ring with the superconducting RF cavities

As part of the Phase III luminosity upgrade, the Cornell Electron-Positron Storage Ring (CESR) RF system has been upgraded from normal conducting (NRF) to superconducting (SRF) cavities. The new superconducting cavities change the overall impedance of CESR and thus change the longitudinal bunch distribution. Measurements of the single bunch longitudinal distribution have been made using a streak camera on CESR with the SRF cavities present. These measurements are compared with earlier measurements on CESR with the NRF cavities. The CESR vacuum chamber impedance is determined from the current dependence of the single bunch charge distribution.