Author: Asvesta, F.
Paper Title Page
MOA1I1 Beam Performance with the LHC Injectors Upgrade 1
 
  • G. Rumolo, S.C.P. Albright, R. Alemany-Fernández, M.E. Angoletta, C. Antuono, T. Argyropoulos, F. Asvesta, M.J. Barnes, H. Bartosik, P. Baudrenghien, G. Bellodi, N. Biancacci, C. Bracco, N. Bruchon, E. Carlier, J. Coupard, H. Damerau, G.P. Di Giovanni, A. Findlay, M.A. Fraser, A. Funken, R. Garoby, S.S. Gilardoni, B. Goddard, G. Hagmann, K. Hanke, A. Huschauer, G. Iadarola, V. Kain, I. Karpov, J.-B. Lallement, A. Lasheen, T.E. Levens, K.S.B. Li, A.M. Lombardi, E.H. Maclean, D. Manglunki, I. Mases Solé, M. Meddahi, L. Mether, B. Mikulec, E. Montesinos, Y. Papaphilippou, G. Papotti, K. Paraschou, C. Pasquino, F. Pedrosa, T. Prebibaj, S. Prodon, D. Quartullo, F. Roncarolo, B. Salvant, M. Schenk, R. Scrivens, E.N. Shaposhnikova, L. Sito, P.K. Skowroński, A. Spierer, R. Steerenberg, M. Sullivan, F.M. Velotti, R. Veness, C. Vollinger, R. Wegner, C. Zannini, E. de la Fuente
    CERN, Meyrin, Switzerland
  • T. Prebibaj
    IAP, Frankfurt am Main, Germany
 
  The LHC Injectors Upgrade (LIU) project was put in place between 2010 and 2021 to increase the intensity and brightness in the LHC injectors to match the challenging requirements of the High-Luminosity LHC (HL-LHC) project, while ensuring reliable operation of the injectors complex up to the end of the HL-LHC era (ca. 2040). During the 2019-2020 CERN accelerators shutdown, extensive hardware modifications were implemented in the entire LHC proton and ion injection chains, involving the new Linac4, the Proton Synchrotron Booster (PSB), the Proton Synchrotron (PS), the Super Proton Synchrotron (SPS) and the ion PS injectors, i.e. the Linac3 and the Low Energy Ion Ring (LEIR). Since 2021, beams have been recommissioned throughout the injectors’ chain and the beam parameters are being gradually ramped up to meet the LIU specifications using new beam dynamics solutions adapted to the upgraded accelerators. This paper focuses on the proton beams and describes the current state of the art.  
slides icon Slides MOA1I1 [10.002 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-HB2023-MOA1I1  
About • Received ※ 29 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 18 October 2023
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TUC3I2 Shaping High Brightness and Fixed Target Beams with the CERN PSB Charge Exchange Injection 135
 
  • C. Bracco, S.C.P. Albright, F. Asvesta, G.P. Di Giovanni, F. Roncarolo
    CERN, Meyrin, Switzerland
 
  CERN adopted the charge exchange injection technique for the first time in the PS Booster after Long Shutdown 2. This allowed to overcome space charge limitations, tailor high brightness beams for the LHC and deliver high intensity flux of protons to the fixed target experiments. Details on the concept, physics, hardware and diagnostic tools are presented while retracing the exciting steps of the successful commissioning period and the first years of operation with this system. A look to the future is taken by explaining the next stages to achieve the ambitious Luminosity targets foreseen for the HL-LHC era.  
slides icon Slides TUC3I2 [19.053 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC3I2  
About • Received ※ 01 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 24 October 2023
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WEA1I2 Analytical and Numerical Studies on Kicked Beams in the Context of Half-Integer Studies 188
 
  • G. Franchetti
    GSI, Darmstadt, Germany
  • F. Asvesta, H. Bartosik, T. Prebibaj
    CERN, Meyrin, Switzerland
 
  In the context of the half-integer studies an investigation of the dynamics of the kicked beam has revealed surprising properties. The coupling of space charge with chromatic- ity in addition to usual damping/non-damping dynamics, exhibits new properties typical of a linear coupling. This proceeding covers the status of these studies carried out with analytical and numerical approaches and the prelimi- nary results of experimental investigations in the CERN PS Booster.  
slides icon Slides WEA1I2 [24.966 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA1I2  
About • Received ※ 02 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 13 October 2023 — Issued ※ 24 October 2023
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WEA2C2 Measurement of Transverse Statistical Dependence for Non-Gaussian Beam Distributions via Resonances in the CERN PSB 231
 
  • E.R. Lamb, F. Asvesta, H. Bartosik, G. Sterbini
    CERN, Meyrin, Switzerland
  • E.R. Lamb
    EPFL, Lausanne, Switzerland
 
  This work addresses the origins and the effects of the statistical dependence in non-Gaussian beam distributions with the ultimate goal to identify the most representative case for tracking simulations across the CERN accelerator complex. Starting from the observation that non-Gaussian heavy-tailed transverse beam profiles can be reconstructed from 4D phase space distributions under two different conditions (statistical independence or dependence in the x-y plane), we consider space charge dominated beams interacting with the lattice nonlinear resonances to perform measurements to study the mechanisms that lead to non-Gaussian distributions. Finally, we explore the beam dynamics implications of the above hypotheses in terms of dependent loss processes across the transverse planes.  
slides icon Slides WEA2C2 [1.249 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA2C2  
About • Received ※ 30 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 21 October 2023
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THBP09 Pushing High Intensity and High Brightness Limits in the CERN PSB after the LIU Upgrades 458
 
  • F. Asvesta, S.C.P. Albright, H. Bartosik, C. Bracco, G.P. Di Giovanni, T. Prebibaj
    CERN, Meyrin, Switzerland
 
  After the successful completion of the LHC Injectors Upgrade (LIU) project, the CERN Proton Synchrotron Booster (PSB) has produced beams with up to two times higher brightness. However, the efforts to continuously improve the beam quality for the CERN physics experiments are ongoing. In particular, the high brightness LHC beams show non-Gaussian tails in the transverse profiles that can cause losses in the downstream machines, and even at LHC injection. As a result, alternative production schemes based on triple harmonic capture are being investigated in order to preserve brightness and reduce transverse tails at the same time. In addition, in view of a possible upgrade to the ISOLDE facility that would require approximately twice the number of protons per ring, the ultimate intensity reach of the PSB is explored. In this context, injection schemes using painting both transversely and longitudinally in order to mitigate the strong space charge effects are developed.  
poster icon Poster THBP09 [0.751 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP09  
About • Received ※ 28 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 20 October 2023
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THBP19 Experimental Investigations on the High-Intensity Effects Near the Half-Integer Resonance in the PSB 499
 
  • T. Prebibaj, F. Antoniou, F. Asvesta, H. Bartosik
    CERN, Meyrin, Switzerland
  • G. Franchetti
    GSI, Darmstadt, Germany
 
  Space charge effects are the main limitation for the brightness performance of the Proton Synchrotron Booster (PSB) at CERN. Following the upgrades of the LHC Injectors Upgrade (LIU) project, the PSB delivered unprecedented brightness even exceeding the projected target parameters. A possibility for further increasing the brightness is to operate above the half-integer resonance 2Qy=9 in order to avoid emittance blow-up from resonances at Qx,y=4 due to the strong space charge detuning. The half-integer resonance can be compensated to a great extent using the available quadrupole correctors in the PSB, and also deliberately excited in a controlled way. The control of the half-integer resonance and the flexibility of the PSB to create a variety of different beam and machine conditions allowed the experimental characterization of space charge effects near this resonance. This contribution reports the experimental observations of the particle trapping during the dynamic crossing of the half-integer, as well as systematic studies of the beam degradation from space charge induced resonance crossing.  
poster icon Poster THBP19 [3.077 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP19  
About • Received ※ 30 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 23 October 2023
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THBP38 Two-Dimensional Longitudinal Painting at Injection into the CERN PS Booster 563
 
  • S.C.P. Albright, F. Asvesta, B. Bielawski, C. Bracco, P.K. Skowroński, R. Wegner
    CERN, Meyrin, Switzerland
 
  To inject highest beam intensities at the transfer from Linac4 into the four rings of the PS Booster (PSB) at CERN, protons must be accumulated during up to 148 turns in total. With the conventional, fixed chopping pattern this process results in an approximately rectangular distribution in the longitudinal phase space. As the bucket shape in the PSB does not correspond to this distribution, the process leads to longitudinal mismatch, contributing to emittance growth and reduced transmission. The field in the last accelerating cavity of Linac4 can be modulated, which leads to fine corrections of the extracted beam energy. At the same time, the chopping pattern can be varied. Combining both allows injecting a near uniform longitudinal distribution whose boundary corresponds to an iso-Hamiltonian contour of the RF bucket, hence significantly reducing mismatch. In an operational context, the longitudinal painting must be controlled in a way that allows easy intensity variation, and can even require different painting configurations for each of the four PSB rings. This contribution presents the first demonstration of longitudinal painting in the PSB, and its impact on beam performance.  
DOI • reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP38  
About • Received ※ 30 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 24 October 2023
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