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Valishev, A.

Paper Title Page
MOPLS040 Magnet Structure of the VEPP-2000 Electron-positron Collider 628
 
  • P.Yu. Shatunov, D.E. Berkaev, A.A. Borisov, I. Koop, N.A. Mezentsev, E. Perevedentsev, Y.M. Shatunov, D.B. Shwartz
    BINP SB RAS, Novosibirsk
  • A. Valishev
    Fermilab, Batavia, Illinois
 
  Electron-positron collider VEPP-2000 with beam energy up to 1 GeV is under commissioning at Budker Institute. This paper presents magnetic elements of the storage ring including 13T focusing superconducting solenoids in interaction regions. Features of magnet elements design and magnetic measurements results are given together with comparison to previously calculated data.  
WEPCH057 Measurement and Optimization of the Lattice Functions in the Debuncher Ring at Fermilab 2050
 
  • V.P. Nagaslaev, K. Gollwitzer, V.A. Lebedev, A. Valishev
    Fermilab, Batavia, Illinois
  • V. Sajaev
    ANL, Argonne, Illinois
 
  A goal of the Tevatron Run-II upgrade requires substantial increase of antiproton production. The central step towards this goal is increasing the Debuncher ring admittance. Detailed understanding of the Debuncher's optics, aperture limitations and lattice functions is necessary. The method of the response matrix optimization has been used to determine quadrupole errors and corrections to the design functions. The measurement accuracy is about 5% due to the Beam Position Monitor system resolution and the small number of steering elements in the machine. We have used these accurate measurements to redesign the machine optics to maximize the acceptance of the Debuncher where the main limiting apertures are the stochastic cooling pickups and kickers. Accuracy of the measurements and the limitations are discussed as well as details of the optics modification.  
WEPCH058 Progress with Collision Optics of the Fermilab Tevatron Collider 2053
 
  • A. Valishev, Y. Alexahin, G. Annala, V.A. Lebedev, V.P. Nagaslaev
    Fermilab, Batavia, Illinois
  • V. Sajaev
    ANL, Argonne, Illinois
 
  Recent advances in the measurement and modeling of the machine parameters and lattice functions at the Tevatron allowed modifications of the collision optics to be performed in order to increase the collider luminosity. As the result, beta functions in the two collision points were decreased from 35cm to 29cm which resulted in ~10% increase of the peak luminosity. In this report we describe the results of optics measurements and corrections. We also discuss planned improvements, including the new betatron tune working point and correction of the beta function chromaticity.  
WEPCH059 Linear Lattice Modeling of the Recycler Ring at Fermilab 2056
 
  • M. Xiao, V.P. Nagaslaev, A. Valishev
    Fermilab, Batavia, Illinois
  • V. Sajaev
    ANL, Argonne, Illinois
 
  The Recycler Ring at Fermilab is a fixed 8 GeV kinetic energy storage ring, by the use of permanent magnets in the ring lattice. It is a strong focusing FODO lattice made up of either two gradient magnets or two quadrupoles(in dispersion free straight sections). The magnetic properties of all magnets used were measured before installation and surveyed in place to minimize possible errors. Nevertheless, substantial differences are found in tunes and beta functions between the existing linear model and the real storage ring. It results in difficulties when tuning the machine to new lattice conditions. We are trying to correct the errors by matching the model into the real machine using Orbit Response Matrix(ORM) method. The challenge with ORM particular in this ring and the results are presented in this paper.  
WEPCH096 Measurement and Correction of the 3rd Order Resonance in the Tevatron 2140
 
  • F. Schmidt
    CERN, Geneva
  • Y. Alexahin, V.A. Lebedev, D. Still, A. Valishev
    Fermilab, Batavia, Illinois
 
  At Fermilab Tevatron BPM system has been recently upgraded resulting much better accuracy of beam position measurements and improvements of data acquisition for turn-by-turn measurements. That allows one to record the beam position at each turn for 8000 turns for all BPMs (118 in each plane) with accuracy of about 10-20 μm. In the last decade a harmonic analysis tool has been developed at CERN that allows relating each FFT line derived from the BPM data with a particular non-linear resonance in the machine. In fact, one can even detect the longitudinal position of the sources of these resonances. Experiments have been performed at the Tevatron in which beams have been kicked to various amplitudes to analyze the 3rd order resonance. It was possible to address this rather large resonance to some purposely powered sextupoles. An alternative sextupole scheme allowed the suppression of this resonance by a good factor of 2. Lastly, the experimental data are compared with model calculations.