• Y. Li, X. Liu, V. Medjidzade, M.A. Palmer, D.H. Rice, D. L. Rubin, J.J. Savino
  CLASSE, Ithaca, New York

Funding: Work supported by the National Science Foundation, the US Department of Energy, and the Japan/US Cooperation Program

In concert with the ILC global design effort, the CESR is being converted into ILC Damping Ring Test Accelerator. The vacuum system is undergoing staged reconfigurations to support both the CesrTA physics goals and the CHESS X-ray sources. Six superconducting wigglers were moved to a sector with zero-dispersion. The sector is densely populated with beam instrumentation and diagnostic devices. A new photon stop chamber will be used to handle the high synchrotron radiation power generated from the SCWs at high positron beam energy. A 12-m long gate-valve isolated straight sector was created in a second location, where many electron-cloud diagnostic chambers will be installed and tested. We also configured two very short sections in the arcs, with additional gate valves, to provide flexibility of exchanging various meter-long test chambers with minimum impact to the operations. Many retarding field analyzers were integrated into the vacuum modifications in SCWs, dipoles, and drifts to study EC growth and suppression techniques. Creating environments where both local and collaborator provided equipment can be easily installed has been a major objective in the modifications.

• I.V. Bazarov, S.A. Belomestnykh, E.P. Chojnacki, J. Dobbins, B.M. Dunham, R.D. Ehrlich, M.J. Forster, C.M. Gulliford, G.H. Hoffstaetter, Y. Li, M. Liepe, X. Liu, F. Löhl, D.G. Ouzounov, H. Padamsee, D.H. Rice, V.D. Shemelin, E.N. Smith, K.W. Smolenski, M. Tigner, V. Veshcherevich
  CLASSE, Ithaca, New York
• H. Li
  Cornell University, Ithaca, New York
• H. K. Sayed
  JLAB, Newport News, Virginia

Cornell University has built a high average current electron injector for use with an Energy Recovery Linac. The injector is capable of up to 100 mA average current at 5 MeV (33 mA at 15 MeV) and is expected to produce the ultra low emittances needed for an ERL. This talk will give an overview of the initial performance of this injector and summarize a spectrum of beam physics experiments undertaken to demonstrate low emittance, high average current operation.

Slides

• M.A. Palmer, M.G. Billing, J.R. Calvey, G.W. Codner, S. Greenwald, Y. Li, X. Liu, J.A. Livezey, R.E. Meller, R.M. Schwartz, J.P. Sikora, C.R. Strohman, W.S. Whitney, T. Wilksen
  CLASSE, Ithaca, New York

Funding: Support provided by the US National Science Foundation and the US Department of Energy.

A central component of the operation of the Cornell Electron Storage Ring as a Test Accelerator (CesrTA) for ILC Damping Rings R&D is the characterization of electron cloud growth in each of the principal vacuum chamber types in use in the storage ring. In order to facilitate measurements in chambers with tightly constrained external apertures, retarding field analyzers have been developed that can be deployed in regions with as little as 3mm of available aperture. We report on the design, fabrication, characterization and operation of devices that are presently deployed in CESR drift, dipole, and wiggler chambers.

• M.A. Palmer, J.P. Alexander, M.G. Billing, J.R. Calvey, S.S. Chapman, G.W. Codner, C.J. Conolly, J.A. Crittenden, J. Dobbins, G. Dugan, E. Fontes, M.J. Forster, R.E. Gallagher, S.W. Gray, S. Greenwald, D.L. Hartill, W.H. Hopkins, J. Kandaswamy, D.L. Kreinick, Y. Li, X. Liu, J.A. Livezey, A. Lyndaker, V. Medjidzade, R.E. Meller, S.B. Peck, D.P. Peterson, M.C. Rendina, P. Revesz, D.H. Rice, N.T. Rider, D. L. Rubin, D. Sagan, J.J. Savino, R.D. Seeley, J.W. Sexton, J.P. Shanks, J.P. Sikora, K.W. Smolenski, C.R. Strohman, A.B. Temnykh, M. Tigner, S. Vishniakou, W.S. Whitney, T. Wilksen, H.A. Williams
  CLASSE, Ithaca, New York
• J.M. Byrd, C.M. Celata, J.N. Corlett, S. De Santis, M.A. Furman, A. Jackson, R. Kraft, D.V. Munson, G. Penn, D.W. Plate, A.W. Rawlins, M. Venturini, M.S. Zisman
  LBNL, Berkeley, California
• J.W. Flanagan, P. Jain, K. Kanazawa, K. Ohmi, H. Sakai, K. Shibata, Y. Suetsugu
  KEK, Ibaraki
• K.C. Harkay
  ANL, Argonne
• Y. He, M.C. Ross, C.-Y. Tan, R.M. Zwaska
  Fermilab, Batavia
• R. Holtzapple
  CalPoly, San Luis Obispo, CA
• J.K. Jones
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• D. Kharakh, M.T.F. Pivi, L. Wang
  SLAC, Menlo Park, California
• E.N. Smith
  Cornell University, Ithaca, New York
• A. Wolski
  Cockcroft Institute, Warrington, Cheshire

Funding: Support provided by the US National Science Foundation, the US Department of Energy, and the Japan/US Cooperation Program.

In March of 2008, the Cornell Electron Storage Ring (CESR) concluded twenty eight years of colliding beam operations for the CLEO high energy physics experiment. We have reconfigured CESR as an ultra low emittance damping ring for use as a test accelerator (CesrTA) for International Linear Collider (ILC) damping ring R&D. The primary goals of the CesrTA program are to achieve a beam emittance approaching that of the ILC Damping Rings with a positron beam, to investigate the interaction of the electron cloud with both low emittance positron and electron beams, to explore methods to suppress the electron cloud, and to develop suitable advanced instrumentation required for these experimental studies (in particular a fast x-ray beam size monitor capable of single pass measurements of individual bunches). We report on progress with the CESR conversion activities, the status and schedule for the experimental program, and the first experimental results that have been obtained.

Slides