Author: Antoniou, F.
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MOPOST056 Interplay between Space Charge and Intra-beam Scattering for the CERN Ion Injectors 214
SUSPMF073   use link to see paper's listing under its alternate paper code  
 
  • M. Zampetakis, F. Antoniou, F. Asvesta, H. Bartosik, Y. Papaphilippou
    CERN, Meyrin, Switzerland
 
  The CERN ion injectors, SPS and LEIR, operate in a strong space charge and intra-beam scattering regime, which can lead to degradation of their beam performance. To optimize machine performance requires thus to study the interplay of these two effects in combined space charge and intrabeam scattering tracking simulations. In this respect, the kinetic theory approach of intra-beam scattering has been implemented in pyORBIT and benchmarked against analytical models. First results of combined space charge and intra-beam scattering simulations for SPS and LEIR are presented in this contribution. The simulation results are compared with observations from beam measurements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST056  
About • Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 07 July 2022
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MOPOST057 Characterization of the Vertical Beam Tails in the CERN PS Booster 218
 
  • T. Prebibaj, F. Antoniou, F. Asvesta, H. Bartosik, C. Bracco, G.P. Di Giovanni, E. Renner
    CERN, Meyrin, Switzerland
 
  The CERN Proton Synchrotron Booster (PSB) went through major upgrades in the framework of the LHC Injectors Upgrade Project (LIU) aiming to double the brightness of the LHC beams. Operation restarted in early 2021, demonstrating the expected performance improvement. The high-brightness beams, nevertheless, appear to have overpopulated tails in the vertical beam profiles, both at injection and at extraction energies. In an attempt to understand the origin and evolution of the observed tails, systematic profile measurements were performed for different machine and beam configurations using Wire Scanners (WS). The results are presented in this report and compared to simulations. The effect of the Coulomb scattering of the wire to the beam distribution is also addressed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST057  
About • Received ※ 03 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 24 June 2022
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MOPOST058 Studies on the Vertical Half-Integer Resonance in the CERN PS Booster 222
SUSPMF074   use link to see paper's listing under its alternate paper code  
 
  • T. Prebibaj, F. Antoniou, F. Asvesta, H. Bartosik
    CERN, Meyrin, Switzerland
  • G. Franchetti
    GSI, Darmstadt, Germany
 
  Following the upgrades of the LHC Injectors Upgrade Project (LIU), the Proton Synchrotron Booster (PSB) at CERN successfully delivers beams with double brightness. An important contributing factor for this was the dynamic correction of the beta-beating induced by the injection chicane, which allowed stable operation closer to the half-integer resonance. Ideally, injection above the half-integer resonance could further improve the beam brightness. In this context, a series of studies were initiated in order to characterize the effects of space charge when crossing the half-integer resonance. In this contribution, the first results of these investigations are reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST058  
About • Received ※ 03 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 24 June 2022
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MOPOTK028 Zero Dispersion Optics to Improve Horizontal Emittance Measurements at the CERN Proton Synchrotron 503
 
  • W. Van Goethem, F. Antoniou, F. Asvesta, H. Bartosik, A. Huschauer
    CERN, Meyrin, Switzerland
 
  In modern particle accelerators, the horizontal dispersion function is forced to zero at locations with instrumentation measuring the transverse beam distribution, in order to remove the dispersive contribution to the horizontal beam size. The design of the CERN Proton Synchrotron did not foresee such a zero-dispersion insertion, making it challenging to get a good precision on the beam size measurements. In this contribution, we present a new optics configuration, which allows to reach zero horizontal dispersion at the locations of different beam size measurement locations. This can be achieved by powering a set of trim quadrupoles, the so-called Low Energy Quadrupoles (LEQ). We investigate how the resulting optics perturbation affects beam parameters.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK028  
About • Received ※ 07 June 2022 — Revised ※ 17 June 2022 — Accepted ※ 25 June 2022 — Issue date ※ 08 July 2022
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MOPOTK029 Improved Low-Energy Optics Control for Transverse Emittance Preservation at the CERN Proton Synchrotron 507
SUSPMF055   use link to see paper's listing under its alternate paper code  
 
  • W. Van Goethem, F. Antoniou, F. Asvesta, H. Bartosik, A. Huschauer
    CERN, Meyrin, Switzerland
 
  Preservation of the transverse emittances across the CERN accelerator chain is an important requirement for beams produced for the Large Hadron Collider (LHC). In the CERN Proton Synchrotron (PS), high brightness LHC-type beams are stored on a long flat bottom for up to 1.2 seconds. During this storage time, direct space charge effects may lead to resonance crossing and subsequent growth of the transverse emittances. Previous studies showed an important emittance increase when the PS working point is moved near integer tune values. Subsequent simulation studies confirmed that this observation is caused by an interplay of space charge effects and the optics beatings induced by the Low Energy Quadrupoles (LEQ). A new optics configuration using these quadrupoles to reduce the optics beating and the emittance growth was developed and experimentally validated. The results of simulation and experimental studies are presented in this contribution.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK029  
About • Received ※ 07 June 2022 — Revised ※ 17 June 2022 — Accepted ※ 25 June 2022 — Issue date ※ 10 July 2022
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WEIYGD1 Achievements and Performance Prospects of the Upgraded LHC Injectors 1610
 
  • V. Kain, S.C.P. Albright, R. Alemany-Fernández, M.E. Angoletta, F. Antoniou, T. Argyropoulos, F. Asvesta, B. Balhan, M.J. Barnes, D. Barrientos, H. Bartosik, P. Baudrenghien, G. Bellodi, N. Biancacci, A. Boccardi, J.C.C.M. Borburgh, C. Bracco, E. Carlier, D.G. Cotte, J. Coupard, H. Damerau, G.P. Di Giovanni, A. Findlay, M.A. Fraser, A. Funken, B. Goddard, G. Hagmann, K. Hanke, A. Huschauer, M. Jaussi, I. Karpov, T. Koevener, D. Küchler, J.-B. Lallement, A. Lasheen, T.E. Levens, K.S.B. Li, A.M. Lombardi, N. Madysa, E. Mahner, M. Meddahi, L. Mether, B. Mikulec, J.C. Molendijk, E. Montesinos, D. Nisbet, F.-X. Nuiry, G. Papotti, K. Paraschou, F. Pedrosa, T. Prebibaj, S. Prodon, D. Quartullo, E. Renner, F. Roncarolo, G. Rumolo, B. Salvant, M. Schenk, R. Scrivens, E.N. Shaposhnikova, P.K. Skowroński, A. Spierer, F. Tecker, D. Valuch, F.M. Velotti, R. Wegner, C. Zannini
    CERN, Meyrin, Switzerland
 
  To provide HL-LHC performance, the CERN LHC injector chain underwent a major upgrade during an almost 2-year-long shutdown. In the first half of 2021 the injectors were gradually re-started with the aim to reach at least pre-shutdown parameters for LHC as well as for fixed target beams. The strategy of the commissioning across the complex, a summary of the many challenges and finally the achievements will be presented. Several lessons were learned and have been integrated to define the strategy for the performance ramp-up over the coming years. Remaining limitations and prospects for LHC beam parameters at the exit of the LHC injector chain in the years to come will be discussed. Finally, the emerging need for improved operability of the CERN complex will be addressed, with a description of the first efforts to meet the availability and flexibility requirements of the HL-LHC era while at the same time maximizing fixed target physics output.  
slides icon Slides WEIYGD1 [5.905 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEIYGD1  
About • Received ※ 08 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 09 July 2022  
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WEOZSP2 Suppression of Crab Cavity Noise Induced Emittance Growth by Transverse Beam Coupling Impedance 1659
SUSPMF068   use link to see paper's listing under its alternate paper code  
 
  • N. Triantafyllou, A. Wolski
    The University of Liverpool, Liverpool, United Kingdom
  • F. Antoniou, H. Bartosik, P. Baudrenghien, X. Buffat, R. Calaga, Y. Papaphilippou
    CERN, Meyrin, Switzerland
  • T. Mastoridis
    CalPoly, San Luis Obispo, California, USA
 
  Crab Cavities are a key component of the High Luminosity LHC (HL-LHC) upgrade, as they aim to minimize the luminosity reduction caused by the crossing angle. Two superconducting crab cavities were installed in the Super Proton Synchrotron (SPS) at CERN in 2018 to test their operation in a proton machine for the first time. An important point to consider is the increase in transverse emittance induced by noise in the Low-Level RF (LLRF) system. During the first experimental campaign in 2018, the measured emittance growth was found to be a factor of 4 lower than predicted by the available analytical models. In this report, the effects of transverse beam impedance in the presence of CC LLRF noise on transverse emittance growth are presented and the results of the second experimental campaign, which took place in the SPS in 2021, are discussed.  
slides icon Slides WEOZSP2 [2.694 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEOZSP2  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 15 June 2022
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WEPOTK011 High Intensity Studies in the CERN Proton Synchrotron Booster 2056
 
  • F. Asvesta, S.C.P. Albright, F. Antoniou, H. Bartosik, C. Bracco, G.P. Di Giovanni, G. Rumolo, P.K. Skowroński, C. Zannini
    CERN, Meyrin, Switzerland
  • E. Renner
    TU Vienna, Wien, Austria
 
  After the successful implementation of the LHC Injectors Upgrade (LIU) project, studies were conducted in the CERN Proton Synchrotron Booster (PSB) in order to assess the intensity reach with the increased beam brightness. The studies focused on the high intensity beams delivered to the PSB users, both at 1.4 and 2 GeV. In addition, possible intensity limitations in view of the Physics Beyond Colliders (PBC) Study were investigated. To this end, various machine configurations were tested including different resonance compensation schemes and chromaticity settings in correlation with the longitudinal parameters. This paper summarizes the results obtained since the machine recommissioning.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK011  
About • Received ※ 05 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 19 June 2022
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THPOST003 Collective Effects Estimates for the Damping Ring Design of the FCC-ee 2435
 
  • O. Etisken
    Ankara University, Faculty of Sciences, Ankara, Turkey
  • F. Antoniou, F. Zimmermann
    CERN, Meyrin, Switzerland
  • A. De Santis
    INFN/LNF, Frascati, Italy
  • C. Milardi
    LNF-INFN, Frascati, Italy
 
  The current injector complex design of the FCC-e+e project consists of e+/e linacs, which accelerate the beams up to 6 GeV, a damping ring at 1.54 GeV, a pre-booster ring, accelerating the beam up to 16 GeV and a booster synchrotron ring integrated in the collider tunnel accelerating the beams up to the collision energies. The purpose of the damping ring is to accept the 1.54 GeV beam coming from the linac-1, damp the positron/electron beams and provide the required beam characteristics for the injection into the linac-2. In this presentation the current damping ring design is introduced and analytical calculations on various collective effect such as space charge, intra-beam scattering, longitudinal micro-wave instability, transverse mode coupling instability, ion effects, electron cloud and coherent synchrotron radiation, are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST003  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 08 July 2022
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