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Lebrun, P.

Paper Title Page
TPAP032 Beam-beam Effects in the Tevatron Run II 2245
 
  • V.D. Shiltsev, Y. Alexahin, V. Lebedev, P. Lebrun, R. Moore, T. Sen, A. Valishev, X. Zhang
    Fermilab, Batavia, Illinois
 
  Funding: Work supported by the Universities Research Assos., Inc., under contract DE-AC02-76CH03000 with the U.S. Dept. of Energy.

The Tevatron in Collider Run II (2001-present) is operating with many times higher beam intensities and luminosities than in previous Run I (1992-1995). Electromagnetic long-range and head-on interactions of high intensity proton and antiproton beams have been significant sources of beam loss and lifetime limitations. We present observations of the beam-beam phenomena in the Tevatron and results of relevant beam studies. We analyze the data and various methods employed in operations, predict the performance at upgraded beam parameters and luminosity and discuss possible improvements.

 
RPAT033 Beta Function Measurement in the Tevatron Using Quadrupole Gradient Modulation 2272
 
  • A. Jansson, P. Lebrun, J.T. Volk
    Fermilab, Batavia, Illinois
 
  Funding: Work supported by the U.S. Department of Energy.

Early in Run2, there was an effort to compare the different emittance measurements in the Tevatron (flying wires and synchtotron light) and understand the origin of the observed differences. To measure the beta function at a few key locations near the instruments, air-core quadrupoles were installed. By modulating the gradient of these magents and measuring the effect on the tune, the lattice parameters can be extracted. Initially, the results seem to disagree with with other methods. At the time, the lattice was strongly coupled due to a skew component in the main dipoles, caused by sagging of the cryostat. After a large fraction of the superconducting magnets were shimmed to remove a strong skew quadrupole component, the results now agree with expectations, confirming that the beta function is not the major error source of discrepancy in the emittance measurement.

 
FPAT005 A Betatron Tune Fitting Package for the Tevatron 21.4 MHz Schottky 937
 
  • P. Lebrun, T. Sen, J. You, Z.Y. Yuan
    Fermilab, Batavia, Illinois
  • E. Todesco
    CERN, Geneva
 
  Accurate control of the Betatron tunes and chromaticities is required to optimize the dynamical aperture of any large synchrotron. The Fermilab Tevatron is equipped with two independent Schottky monitors, one operating at 21.4 MHz and the other 1.7 GHz. While the latter one allows us to characterize individual bunches separated by 396 ns, the former one has a larger Q and can give precise tune measurements. A new front-end and related data acquisition for this 21.4 MHz resonator has been installed and commissioned during the FY04 Collider RunII. Output signal are digitized at 100 KHz. Frequency spectra are transfered to dedicated server nodes and fitted in real time. Such frequency spectra are quite complex, due to inherent noise, horizontal/vertical coupling and synchrotron motion. Sophisticated fitting strategies are required. Optimization of this fitting package on relatively powerful commodity computer allows us to report tune and chromaticity measurements at almost 1 Hz. The architecture of the data acquisition system and this fitting package are described and results taken during the FY04 and FY05 runs are presented.  
FPAT008 SDA-Based Diagnostic and Analysis Tools for Collider Run II 1099
 
  • V. Papadimitriou, T.B. Bolshakov, P. Lebrun, S. Panacek, A.J. Slaughter, A. Xiao
    Fermilab, Batavia, Illinois
 
  Funding: Fermilab (Department of Energy).

Operating and improving the understanding of the Fermilab Accelerator Complex for the colliding beam experiments requires advanced software methods and tools. The Shot Data Acquisition and Analysis (SDA) has been developed to fulfill this need. Data is stored in a relational database, and is served to programs and users via Web-based tools. Summary tables are systematically generated during and after a store. These tables, the Supertable, and the Recomputed Emittances and Recomputed Intensity tables are discussed here. This information is also accesible in JAS3 (Java Analysis Studio version 3).

 
FPAT012 Tevatron Beam Lifetimes at Injection Using the Shot Data Analysis System 1279
 
  • A. Xiao, T.B. Bolshakov, P. Lebrun, E.S. McCrory, V. Papadimitriou, A.J. Slaughter
    Fermilab, Batavia, Illinois
 
  The purpose of the Shot Data Acquisition and Analysis (SDA) system is to provide summary data on the Fermilab RunII accelerator complex and provide related software for detailed analyses. In this paper, we discuss such a specific analysis on Tevatron beam lifetimes at injection. These results are based on SDA data, tools and methodology. Beam lifetime is one of our most important diagnostics. An analysis of it can give information on intra beam scattering, aperture limitations, instabilities and most importantly beam-beam effects. Such an analysis gives us a better understanding of our machine, and will lead to an improved performance in the future.