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Zhang, X.

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THPAN117 Electron Cloud Studies at Tevatron and Main Injector 3501
 
  • X. Zhang
  • A. Z. Chen, W. Chou, B. M. Hanna, K. Y. Ng, J.-F. Ostiguy, L. Valerio, R. M. Zwaska
    Fermilab, Batavia, Illinois
  
  Funding: Work supported by the U. S. Department of Energy under Contract No. DE-AC02-76CH03000

Estimates indicate that the electron cloud effect could be a limiting factor for Main Injector intensity upgrades, with or without a the presence of a new 8 GeV superconducting 8GeV Linac injector. The effect may turn out to be an issue of operational relevance for other parts of the Fermilab accelerator complex as well. To improve our understanding of the situation, two sections of specially made vacuum test pipe outfitted for electron cloud detection with ANL provided Retarding Field Analyzers (RFAs), were installed in the Tevatron and the Main Injector. In this report we present some measurements, compare them with simulations and discuss future plans for studies.

 
THPAN118 Simulations of the Electron Cloud Buildups and Suppressions in Tevatron and Main Injector 3504
 
  • X. Zhang
  • J.-F. Ostiguy
    Fermilab, Batavia, Illinois
  
  Funding: Work supported by the U. S. Department of Energy under Contract No. DE-AC02-76CH03000

To assess the effects of the electron cloud on Main Injector intensity upgrades, simulations of the cloud buildup were carried out using POSINST and compared with ECLOUD. Results indicate that even assuming an optimistic 1.3 maximum secondary electron yield, the electron cloud remains a serious concern for the planned future operational of mode of 500 bunches, 3·1011 proton per bunch. Electron cloud buildup can be mitigated in various ways. We consider a plausible scenario involving solenoids in straight section and a single clearing strip electrode (like SNEG in Tevatron)held at a potential of 500V. Simulations with parameters corresponding to Tevatron and Main Injector operating conditions at locations where special electron cloud detectors have been installed have been carried out and are in satisfactory agreement with preliminary measurements.

 
TUOCKI04 Experimental Demonstration of Beam-Beam Compensation by Tevatron Electron Lenses and Prospects for the LHC 728
 
  • V. D. Shiltsev
  • Y. Alexahin, V. Kamerdzhiev, G. F. Kuznetsov, X. Zhang
    Fermilab, Batavia, Illinois
  • K. Bishofberger
    LANL, Los Alamos, New Mexico
  
  We report the first experimental demonstration of compensation of beam-beam interaction effects with use of electron beams. Long-range and head-on interactions of high intensity proton and antiproton beams have been dominating sources of beam loss and lifetime limitations in the Tevatron in Collider Run II (2001-present). Electron lense acting on proton bunches has doubled their lifetime by compensating beam-beam interaction with antiprotons. We present results of the experiments, operational details and discuss possibilities of using electron lenses for beam-beam compensation in LHC.  
slides icon Slides  
TUPAS024 Experimental and Simulation Studies of Beam-Beam Compensation with Tevatron Electron Lenses 1703
 
  • V. Kamerdzhiev
  • Y. Alexahin, V. D. Shiltsev, A. Valishev, X. Zhang
    Fermilab, Batavia, Illinois
  • D. N. Shatilov
    BINP SB RAS, Novosibirsk
  
  Initially the Tevatron Electron Lenses (TELs) were intended for compensation of the beam-beam effect on the antiproton beam. Owing to recent increase in the number of antiprotons and reduction in their emittance, it is the proton beam now that suffers most from the beam-beam effect. We present results of beam studies, compare them with the results of computer simulations using LIFETRAC code and discuss possibilities of further improvements of the Beam-Beam Compensation efficiency in the Tevatron.  
TUPAS025 Commissioning of the Second Tevatron Electron Lens and Beam Study Results 1706
 
  • V. Kamerdzhiev
  • R. J. Hively, G. F. Kuznetsov, H. Pfeffer, G. W. Saewert, V. D. Shiltsev, X. Zhang
    Fermilab, Batavia, Illinois
  
  In the framework of Fermilab's Beam-Beam Compensation project the second Tevatron Electron Lens (TEL2) has been installed in the Tevatron during Spring 2006 shutdown. After successful commissioning a series of beam studies has been carried out in single bunch mode. The paper describes the commissioning process and first beam studies results.