• R. Holtzapple, J. S. Kern
  Alfred University, Alfred, New York
• G. W. Codner, M. A. Palmer, E. Tanke
  CESR-LEPP, Ithaca, New York

Presently, CESR is operated at two different beam energies, low energy (E=2GeV) for high energy physics (CESR-c), and high energy (E=5.3GeV) for synchrotron radiation production (CHESS). The electron and positron bunches vertical dynamics at these two energies are vastly different, in part due to the change in the pretzel orbit, the presence of wiggler magnets at low energy, and synchrotron radiation power at two vastly different energies. Using the 32 channel photomultiplier array*, we measured the vertical beam dynamics on a turn-by-turn basis during CHESS and CESR-c operation as well as dedicated machine studies time. For these studies we quantify the electron cloud effects such as vertical tune shift and vertical beam size blow-up along the electron and positron trains at these two vastly different beam energies. In addition, the turn-by-turn capability of the PMT array allows us to study the vertical bunch dynamics over 10k turns.

* Design and Implementation of an Electron and Positron Multibunch Turn-by-Turn Vertical Beam Profile Monitor in CESR-PAC2007 proceedings

• M. A. Palmer, E. Tanke
  CESR-LEPP, Ithaca, New York
• B. Cerio, R. Holtzapple, J. S. Kern
  Alfred University, Alfred, New York
• J. Dobbins, D. L. Hartill, C. R. Strohman
  CLASSE, Ithaca
• M. E. Watkins
  CMU, Pittsburgh, Pennsylvania

A fast vertical beam profile monitor has been implemented at the Cornell Electron Storage Ring (CESR). Readout is based on the Hamamatsu H7260K multianode photomultiplier. This device has a 32 channel linear anode array with 1 mm channel pitch and sub-nanosecond rise time. It provides the ability to probe individual electron and position bunches which are separated by 14 ns within the trains in CESR. A custom 72 MHz digitizer unit allows synchronous multibunch and turn-by-turn data acquisition. An on-board digital signal processor provides local data processing capability. This system provides the capability to probe a range of single bunch and multibunch beam dynamics issues as well as machine stability issues. In this paper we describe the profile monitor hardware, data acquisition system, calibration of the profile monitor, and data analysis software.