A Study of the Effect of Beam-Beam Interactions on CESR Optics
The CESR storage ring facility has begun operation in an energy region which allows high-statistics investigation of charm-quark bound states. Experience during the first two years has shown that the effects of parasitic crossings in the pretzel orbits present an important factor in injection efficiency, in the beam lifetime and in the stored current limits. We compare the results of beam dynamics and tracking calculations which quantify the effects of these parasitic crossings on optics and dynamic aperture for the injected and stored trajectories to observations of beam behavior.
Multiparticle phenomena and Landau damping
The purpose of this paper is to survey various methods of studying multiparticle phenomena in accelerators. Both experimental and theoretical methods are described. An effort has been made to emphasize the intuitive and qualitative aspects rather than the detailed mathematics. Some of the terms or concepts to be explained are coherent and incoherent tunes, normal modes, Landau damping, beam‐transfer functions, and feedback. These are all of daily importance in the interpretation of colliding‐beam observations and the control of performance.
An upgrade for the beam position monitoring system at the Cornell Electron Storage Ring
We describe the design and initial characterization of a fast (nanosecond time scale), high resolution (micron level) beam position monitoring system for use in the Cornell Electron Storage Ring (CESR). Beam position monitoring requirements at CESR include 1) precision orbit measurements in the interaction region and near the synchrotron x-ray beam lines, 2) monitoring of individual bunch positions during multi-bunch high energy physics (HEP) operation, 3) single pass measurements to monitor injected bunch oscillations and injection transients, and 4) operation at both HEP and injection current levels which vary by 5 orders of magnitude. The ready availability of electronic components with large bandwidth and dynamic range for the communications industry has allowed us to economically implement a system providing this range of capabilities.