Author: Lasocha, K.    [Łasocha, K.]
Paper Title Page
THC2I2 Extraction of LHC Beam Parameters from Schottky Signals 382
 
  • K. Łasocha, D. Alves, C. Lannoy, N. Mounet
    CERN, Meyrin, Switzerland
  • C. Lannoy, T. Pieloni
    EPFL, Lausanne, Switzerland
 
  Analysis of Schottky signals provides rich insights into the dynamics of a hadron beam, with well-established methods of deriving the betatron tune and machine chromaticity. In this contribution, we will report on recent developments in the analysis and understanding of the signals measured at the Large Hadron Collider during proton and Pb82+ fills. A fitting-based technique, where the measured spectra are iteratively compared with theoretical predictions, will be presented and compared with the previous methods. As a step beyond the classical theory of Schottky spectra, certain signal modifications due to the activity of the LHC machine systems will be discussed from the perspective of the applicability of the modified signal to the beam diagnostics.  
slides icon Slides THC2I2 [9.053 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-HB2023-THC2I2  
About • Received ※ 04 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 12 October 2023
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THBP47 Studies on the Effect of Beam-Coupling Impedance on Schottky Spectra of Bunched Beams 595
 
  • C. Lannoy, D. Alves, K. Łasocha, N. Mounet
    CERN, Meyrin, Switzerland
  • C. Lannoy, T. Pieloni
    EPFL, Lausanne, Switzerland
 
  Schottky monitors can be used for non-invasive beam diagnostics to estimate various bunch characteristics, such as tune, chromaticity, bunch profile or synchrotron frequency distribution. However, collective effects, in particular beam-coupling impedance, can significantly affect Schottky spectra when large bunch charges are involved. In such conditions, the available interpretation methods are difficult to apply directly to the measured spectra, thus preventing the extraction of beam and machine parameters, which is possible for lower bunch charges. To study the impact of impedance on such spectra, we perform here time-domain, macro-particle simulations and apply a semi-analytical method to compute the Schottky signal for various machine and beam conditions, including those corresponding to typical physics operation at the Large Hadron Collider. This study provides preliminary interpretations of the impact of beam-coupling impedance on Schottky spectra by incorporating longitudinal and transverse resonator-like impedance models into the simulations.  
poster icon Poster THBP47 [1.133 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP47  
About • Received ※ 01 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 21 October 2023
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