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Crittenden, J.A.

Paper Title Page
MPPT034 Field Modelling for the CESR-c Superconducting Wiggler Magnets 2336
 
  • J.A. Crittenden, A.A. Mikhailichenko, A. Temnykh
    Cornell University, Department of Physics, Ithaca, New York
  • E.N. Smith, K.W. Smolenski
    Cornell University, Ithaca, New York
 
  Funding: National Science Foundation.

Superconducting wiggler magnets for operation of the CESR electron-storage ring at energies as low as 1.5 \gev have been designed, built and installed in the years 2000 to 2004. Finite-element models of field quality have been developed, various sources of field errors investigated and compared to field measurements. Minimization algorithms providing accurate analytic representations of the wiggler fields have been established. We present quantitative descriptions of field modelling, of measured field quality and of the accuracy achieved in the analytic functions of the field.

 
MPPT080 Design, Fabrication and Characterization of a Large-Aperture Quadrupole Magnet for CESR-c 4063
 
  • M.A. Palmer, J.A. Crittenden, J. Kandaswamy, A. Temnykh
    Cornell University, Department of Physics, Ithaca, New York
  • T.I. O'Connell
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
 
  Funding: National Science Foundation.

Installation of a radiative Bhabha luminosity monitor for CESR-c operation in 2004 required replacing a 40-mm aperture steel quadrupole magnet with one of aperture 75 mm, while maintaining field-quality tolerances at the level of a few parts in $104. We present the design methodology using 2D- and 3D-finite-element field calculations, compare the calculated 3D integrals to flip-coil measurements, and discuss related mechanical tolerances.

 
TPPP011 Investigations of Injection Orbits at CESR Based on Turn-By-Turn BPM Measurements 1228
 
  • M.G. Billing, J.A. Crittenden, M.A. Palmer
    Cornell University, Department of Physics, Ithaca, New York
 
  Funding: National Science Foundation.

Development of a data acquisition permitting turn-by-turn orbit measurements has been employed at CESR to study the optics of the injected electron beam. An optimization algorithm uses these measurements to determine the effective lattice functions describing the behavior of the injected electrons. We present comparisons of these measurements to tracking calculations of injection acceptance envelopes which account for the parasitic beam-beam interactions with the stored positron beam.

 
TPPP012 A Study of the Effect of Beam-Beam Interactions on CESR Optics 1275
 
  • J.A. Crittenden, M.G. Billing
    Cornell University, Department of Physics, Ithaca, New York
  • D. L. Rubin
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
 
  Funding: National Science Foundation.

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 year has shown that the effects of parasitic crossings in the pretzel orbits present an important factor in injection efficiency, in the beam lifetime and 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.