Keyword: luminosity
Paper Title Other Keywords Page
MOXC01 Combined Effect of Beam-Beam Interaction and Beam Coupling Impedance in Future Circular Colliders impedance, collider, synchrotron, simulation 25
 
  • Y. Zhang, N. Wang
    IHEP, Beijing, People’s Republic of China
  • E. Carideo
    CERN, Geneva, Switzerland
  • M. Migliorati
    SBAI, Roma, Italy
  • M. Zobov
    INFN/LNF, Frascati, Italy
  
  Funding: This work is supported by National Key Programme for S&T Research and Development, China (Grant No. 2016YFA0400400), National Natural Science Foundation of China (No. 11775238, No. 11775239).
The future large scale electron-positron colliders, such as FCC-ee in Europe and CEPC in China, will rely on the crab waist collision scheme with a large Piwinski angle. Differently from the past generation colliders both luminosity and beam-beam tune shifts depend on the bunch length in such a collision scheme. In addition, for the future circular colliders with extreme beam parameters in collision several new effects become important such as beamstrahlung, coherent X-Z instability and 3D flip-flop. For all these effects the longitudinal beam dynamics plays an essential role and should be taken into account for the collider luminosity optimization. In this paper we discuss an impact of the longitudinal beam coupling impedance on the collider performance. 		 
slides icon Slides MOXC01 [2.269 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOXC01  
About • paper received ※ 17 May 2021       paper accepted ※ 27 July 2021       issue date ※ 17 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB003 Machine Learning Analysis of Electron Cooler Operation for RHIC electron, operation, scattering, GUI 45
 
  • X. Gu, A.V. Fedotov, D. Kayran
    BNL, Upton, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
A regression machine learning algorithm was applied to analyze the operation data of RHIC with electron cooler LEReC during the 2020 physics run. After constructing a black-box surrogate model from the XGBoost algorithm and plotting their partial dependency plots for different operation parameters, we can find the effects of an individual parameter on the RHIC luminosity and optimize it accordingly offline. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB003  
About • paper received ※ 14 May 2021       paper accepted ※ 25 May 2021       issue date ※ 11 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB005 Studies for an LHC Pilot Run with Oxygen Beams target, MMI, operation, proton 53
 
  • R. Bruce, R. Alemany-Fernández, H. Bartosik, M.A. Jebramcik, J.M. Jowett, M. Schaumann
    CERN, Geneva, Switzerland
  
  Motivated by the study of collective effects in small systems with oxygen-oxygen (O-O) collisions, and improvements to the understanding of high-energy cosmic ray interactions from proton-oxygen (p-O) collisions, a short LHC oxygen run during Run 3 has been proposed. This article presents estimates for the obtainable luminosity performance in these two running modes based on simulations of a typical fill. The requested integrated luminosity, projected beam conditions, data-taking and commissioning times are considered and a running scenario is proposed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB005  
About • paper received ※ 17 May 2021       paper accepted ※ 25 May 2021       issue date ※ 19 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB007 Prospect for Interaction Region Local Coupling Correction in the LHC Run 3 coupling, optics, quadrupole, MMI 61
 
  • F. Soubelet, T.H.B. Persson, R. Tomás García
    CERN, Geneva, Switzerland
  • O. Apsimon, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • O. Apsimon, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  
  Funding: This work was supported by STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) and CERN.
Successful operation of large scale particle accelerators depends on the precise correction of unavoidable magnet field or alignment errors present in the machine. In the LHC Run 2, local linear coupling in the Interaction Regions (IR) has been proven to have a severe impact on beam size and hence the luminosity - up to a 50% decrease -, making its handling a target for Run 3 and High Luminosity LHC (HL-LHC). However, current measurement methods are not optimised for local IR coupling. In this contribution, an approach to accurately minimise IR local coupling based on correlated external variables such as the |C-| is proposed. The validity of the method is demonstrated through simulations and benchmarked against theoretical values, such as Resonance Driving Terms (RDTs) and Ripken parameters. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB007  
About • paper received ※ 17 May 2021       paper accepted ※ 23 July 2021       issue date ※ 19 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB008 Exploiting the Beam-Beam Wire Demonstrators in the Next LHC Run 3 octupole, operation, experiment, quadrupole 65
 
  • A. Poyet
    Université Grenoble Alpes, Grenoble, France
  • S.D. Fartoukh, N. Karastathis, Y. Papaphilippou, A. Rossi, G. Sterbini
    CERN, Geneva, Switzerland
  • K. Skoufaris
    University of Crete, Heraklion, Crete, Greece
  
  After the successful experiments performed during the LHC Run 2 with the Beam-Beam Wire demonstrators installed, on Beam 2, in the frame of the HL-LHC project, two of the four wire demonstrators were moved to Beam 1. The objective is to gain operational experience with the wire compensation also on that beam and therefore fully exploit the demonstrators’ potential. This paper proposes a numerical validation of the wire implementation using Run 3 scenarios and explores the optimization of those devices in that respect.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB008  
About • paper received ※ 17 May 2021       paper accepted ※ 24 May 2021       issue date ※ 11 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB010 RHIC Beam Energy Scan Operation with Electron Cooling in 2020 operation, electron, emittance, experiment 72
 
  • C. Liu, P. Adams, E.N. Beebe, S. Binello, I. Blackler, M. Blaskiewicz, K.A. Brown, D. Bruno, B.D. Coe, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, C.E. Giorgio, X. Gu, T. Hayes, K. Hock, H. Huang, R.L. Hulsart, T. Kanesue, D. Kayran, N.A. Kling, B. Lepore, Y. Luo, D. Maffei, G.J. Marr, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, J. Morris, C. Naylor, S. Nemesure, M. Okamura, I. Pinayev, S. Polizzo, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, P. Thieberger, M. Valette, A. Zaltsman, I. Zane, K. Zeno, W. Zhang
    BNL, Upton, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
RHIC provided Au-Au collisions at beam energies of 5.75 and 4.59 GeV/nucleon for the physics program in 2020 as a part of the Beam Energy Scan II experiment. The operational experience at these energies will be reported with emphasis on their unique features. These unique features include the addition of a third harmonic RF system to enable a large longitudinal acceptance at 5.75 GeV/nucleon, the application of additional lower frequency cavities for alleviating space charge effects, and the world-first operation of cooling with an RF-accelerated bunched electron beam. 		 
poster icon Poster MOPAB010 [3.523 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB010  
About • paper received ※ 17 May 2021       paper accepted ※ 29 July 2021       issue date ※ 10 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB012 Energy Deposition Study of the CERN HL-LHC Optics v1.5 in the ATLAS and CMS Insertions insertion, proton, optics, radiation 76
 
  • M. Sabaté-Gilarte, F. Cerutti
    CERN, Meyrin, Switzerland
  
  Funding: Research supported by the HL-LHC project
The High Luminosity Large Hadron Collider (HL-LHC) is the approved CERN project aiming at further increasing the integrated luminosity of the LHC by a factor 10. As such, it implies a complete redesign of the experimental high-luminosity insertions of ATLAS and CMS. The progressive evolution of the new layout and optics requires a continuous analysis of the radiation environment, to which magnets and other equipment are exposed to. This is assured by means of Monte Carlo simulations of the collision debris on the evolving machine model. The latter featured several developments, such as the explicit inclusion of the cold protection diodes of the final focusing circuits as well as the crab cavities cryomodule. This work presents the most updated characterization of the radiation field with FLUKA and its impact in the insertion region and the dispersion suppressor of Point 1 and 5, for the HL-LHC optics v1.5 released in 2019. Various optimization and mitigation studies are highlighted, providing key information for maximizing the lifetime of new and present magnets. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB012  
About • paper received ※ 18 May 2021       paper accepted ※ 25 May 2021       issue date ※ 21 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB013 Radiation to Electronics Impact on CERN LHC Operation: Run 2 Overview and HL-LHC Outlook radiation, operation, electron, target 80
 
  • Y.Q. Aguiar, A. Apollonio, F. Cerutti, S. Danzeca, R. García Alía, G. Lerner, D. Prelipcean, M. Sabaté-Gilarte
    CERN, Geneva 23, Switzerland
  
  Funding: Research supported by the HL-LHC project
After the mitigation measures implemented during Run 1 (2010-2012) and Long Shutdown 1 (LS1, 2013-2014), the number of equipment failures due to radiation effects on electronics (R2E) leading to LHC beam dumps and/or machine downtime has been sufficiently low as to yield a minor impact on the accelerator performance. During Run 2 (2015-2018) the R2E related failures per unit of integrated luminosity remained below the target value of 0.5 events/fb-1, with the sole exception of the 2015 run during which the machine commissioning took place. However, during 2018, an increase in the failure rate was observed, linked to the increased radiation levels in the dispersion suppressors of the ATLAS and CMS experimental insertions, significantly affecting the Quench Protection System located underneath the superconducting magnets in the tunnel. This work provides an overview of the Run 2 R2E events during LHC proton-proton operation, putting them in the context of the related radiation levels and equipment sensitivity, and providing an outlook for Run 3 and HL-LHC operation. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB013  
About • paper received ※ 19 May 2021       paper accepted ※ 23 July 2021       issue date ※ 23 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB016 Small Longitudinal Emittance Setup in Injectors with Gold Beam for Beam Energy Scan in RHIC emittance, operation, extraction, cavity 90
 
  • H. Huang, C.J. Gardner, C. Liu, V. Schoefer, K. Zeno
    BNL, Upton, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In recent years, RHIC physics program calls for gold beam collisions with energies at and lower than the nominal RHIC injection energy. To get shorter bunches at the three higher energies (9.8GeV/c, 7.3GeV/c and 4.75GeV/c), RHIC 28MHz cavities were used. The longitudinal emittance out of injectors needs to fit in the 28MHz cavities in RHIC. At two lower energies (4.6 and 3.85 GeV/c), the 9MHz RF cavities were used, which set different requirements from injectors. Extensive beam studies were carried out to establish needed beam parameters, such as bunch intensities and longitudinal emittances. In general, enough intensity can be provided for all energies within the longitudinal emittance constraint. This paper summarizes the recent injector operation experiences for various energies. 		 
poster icon Poster MOPAB016 [2.641 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB016  
About • paper received ※ 16 May 2021       paper accepted ※ 17 August 2021       issue date ※ 01 September 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB027 Improving the Luminosity Burn-Off Estimate by Considering Single-Diffractive Effects scattering, proton, collider, simulation 130
 
  • F.F. Van der Veken, H. Burkhardt, M. Giovannozzi, V.K.B. Olsen
    CERN, Geneva, Switzerland
  
  Collisions in a high-luminosity collider result in a continuous burn-off of the circulating beams that is the dominant effect that reduces the instantaneous luminosity over time. In order to obtain a good estimate of the luminosity evolution, it is imperative to have an accurate understanding of the burn-off. Typically, this is calculated based on the inelastic cross-section, as it provides a direct estimate of the number of protons that participate in inelastic collisions, and are hence removed. Likewise, protons that participate in elastic collisions will remain in the machine acceptance, still contributing to luminosity. In between these two regimes lie diffractive collisions, for which the protons have a certain probability to remain in the machine acceptance. Recent developments of the SixTrack code allow it to interface with Pythia, thus allowing for more precise simulations to obtain a better estimate of the diffractive part of the cross-section. In this paper, we will mainly concentrate on slowly-drifting protons that are close to the acceptance limit, resulting from single-diffractive scattering.  
poster icon Poster MOPAB027 [1.193 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB027  
About • paper received ※ 18 May 2021       paper accepted ※ 31 May 2021       issue date ※ 11 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB029 Burn-Off with Asymmetric Interaction Points emittance, experiment, simulation, controls 138
 
  • R. Tomás García, I. Efthymiopoulos, G. Iadarola
    CERN, Geneva, Switzerland
  
  LHC can host above 2700 proton bunches per ring providing collisions in the ATLAS, CMS, LHCb and ALICE interaction points. ATLAS and CMS are placed symmetrically so that they feature the same colliding bunch pairs. However this is not the case for LHCb, hence introducing unwanted bunch-by-bunch variations of the bunch intensity as the physics fill evolves. We present first analytical derivations, numerical simulations and experimental data in different bunch train collision configurations.  
poster icon Poster MOPAB029 [1.502 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB029  
About • paper received ※ 13 May 2021       paper accepted ※ 25 May 2021       issue date ※ 27 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB033 Monochromatization of e+e− Colliders with a Large Crossing Angle emittance, resonance, collider, radiation 152
 
  • V.I. Telnov
    BINP SB RAS, Novosibirsk, Russia
  
  The relative center-of-mass energy spread at e+e− colliders is much larger than the widths of narrow resonances, which greatly lowers the resonance production rates of J/Psi, Psi-prime, Upsililon(nS), n=1-3. Thus, a significant reduction of the center-of-mass energy spread would open up great opportunities in the search for new physics in rare decays of narrow resonances, the search for new narrow states with small partial e+e− width. The existing monochromatization scheme is only suitable for head-on collisions, while e+e− colliders with crossing angles (the so-called Crab Waist collision scheme) can provide much higher luminosity. In this report, a new monochromatization method for colliders with a large crossing angle is discussed*. The contribution of the beam energy spread to the spread of the center-of-mass energy is canceled by introducing an appropriate energy-angle correlation at the interaction point; the relative RMS mass spread of about (3-5)10-6 seems possible. Limitations of the proposed method are also considered. This monochromatization scheme is very attractive for the Upsilon-meson region and below.
* V.I.Telnov, Monochromatization of e+e− colliders with a large crossing angle, arXiv:2008.13668 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB033  
About • paper received ※ 22 May 2021       paper accepted ※ 26 May 2021       issue date ※ 31 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB034 VEPP-4M Collider Operation at High Energy collider, experiment, electron, positron 155
 
  • P.A. Piminov, G.N. Baranov, A.V. Bogomyagkov, V.M. Borin, V.L. Dorokhov, S.E. Karnaev, K.Yu. Karyukina, V.A. Kiselev, E.B. Levichev, O.I. Meshkov, S.I. Mishnev, I.A. Morozov, I.N. Okunev, E.A. Simonov, S.V. Sinyatkin, E.V. Starostina, A.N. Zhuravlev
    BINP SB RAS, Novosibirsk, Russia
  
  VEPP-4M is an electron positron collider equipped with the universal KEDR detector for HEP experiments in the beam energy range from 1 GeV to 6 GeV. A unique feature of VEPP-4M is the high precision beam energy calibration by resonant polarization technique which allows conducting of interesting experiments despite the low luminosity of the collider. Recently we have started new luminosity acquisition run above 2 GeV. The hadron cross section was measured from 2.3 GeV to 3.5 GeV has been done. The luminosity run for gamma-gamma physics has been started. The luminosity at ψ(1S)-meson has been obtained. For the beam energy calibration the laser polarimeter is used. The paper discusses recent results from VEPP-4M collider.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB034  
About • paper received ※ 18 May 2021       paper accepted ※ 31 May 2021       issue date ※ 22 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB183 A Framework for Dynamic Aperture Studies for Colliding Beams in the High-Luminosity Large Hadron Collider simulation, operation, beam-beam-effects, sextupole 620
 
  • S. Kostoglou, H. Bartosik, Y. Papaphilippou, G. Sterbini
    CERN, Geneva, Switzerland
  
  During the last physics run of the Large Hadron Collider (LHC), Dynamic Aperture (DA) studies have been successfully employed to optimize the accelerator’s performance by guiding the selection of the beam and machine parameters. In this paper, we present a framework for single-particle tracking simulations aiming to refine the envisaged operational scenario of the future LHC upgrade, the High-Luminosity LHC (HL-LHC), including strong non-linear fields such as beam-beam interactions. The impact of several parameters and beam processes during the cycle is initially illustrated with frequency maps and then quantified with DA studies.  
poster icon Poster MOPAB183 [2.789 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB183  
About • paper received ※ 17 May 2021       paper accepted ※ 06 July 2021       issue date ※ 23 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB184 Unsupervised Learning Techniques for Tune Cleaning Measurement ISOL, optics, coupling, quadrupole 624
 
  • H. Garcia Morales
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • E. Fol, R. Tomás García
    CERN, Meyrin, Switzerland
  
  Precise measurements of tune and its stability are crucial for various optics analyses in the LHC, e.g. for the determination of the beta star using K-modulation. LHC BBQ system provides tune measurements online and stores the tune data. We apply unsupervised machine learning techniques on BBQ tune data in order to provide an automatic outlier detection method for better measurements of tune shifts and unexpected tune jitters.  
poster icon Poster MOPAB184 [0.354 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB184  
About • paper received ※ 14 May 2021       paper accepted ※ 09 June 2021       issue date ※ 11 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB230 The Optics Design for the Final Focus System of CLIC 380 GeV optics, sextupole, quadrupole, target 748
 
  • A. Pastushenko, R. Tomás García
    CERN, Geneva, Switzerland
  • A. Faus-Golfe
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  
  The first stage of the Compact Linear Collider (CLIC) is planned to be at the center-of-mass energy of 380 GeV. The final focus system (FFS) was re-optimized for this energy and for L* of 6 m (distance between the Interaction Point (IP) and the last quadrupole, QD0). Furthermore, the FFS optics was optimized for the vertical beta-function of 70 microns to approach the Hourglass effect limit. This paper reports the exploration of shortening the Final Doublet (FD) within the FFS to reduce the chromaticity. In addition, an alternative optics design is investigated with a different dispersion profile along the FFS, which outperforms the previous optics with the same β*, increasing luminosity by 5 %.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB230  
About • paper received ※ 19 May 2021       paper accepted ※ 14 June 2021       issue date ※ 11 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB279 Non-Invasive Beam Profile Monitoring for the HL-LHC Hollow Electron Lens photon, electron, proton, background 884
 
  • A. Salehilashkajani, N. Kumar, O. Sedláček, C.P. Welsch, H.D. Zhang
    The University of Liverpool, Liverpool, United Kingdom
  • M. Ady, N.S. Chritin, N. Jens, O.R. Jones, R. Kersevan, T. Lefèvre, S. Mazzoni, G. Papazoglou, A. Rossi, G. Schneider, R. Veness
    CERN, Geneva, Switzerland
  • P. Forck, S. Udrea
    GSI, Darmstadt, Germany
  • N. Kumar, O. Sedláček, C.P. Welsch, H.D. Zhang
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  
  Funding: This work was supported by the HL-LHC-UK phase II project funded by STFC under Grant Ref: ST/T001925/1 and the STFC Cockcroft core grant No. ST/G008248/1.
A Hollow Electron Lens (HEL) is currently under development for the High-Luminosity upgrade of the Large Hadron Collider (HL-LHC). In this device, a hollow electron beam co-propagates with a central proton beam and provides active halo control in the LHC. To ensure the concentricity of the two beams, a non-invasive diagnostic instrument is currently being commissioned. This instrument is a compact version of an existing prototype that leverages beam induced fluorescence with supersonic gas curtain technology. This contribution includes the design features of this version of the monitor, recent progress, and future plans for tests at the Cockcroft Institute and the electron lens test stand at CERN. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB279  
About • paper received ※ 18 May 2021       paper accepted ※ 15 June 2021       issue date ※ 02 September 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPAB385 An Overview of RF Systems for the EIC cavity, SRF, electron, HOM 1179
 
  • R.A. Rimmer, J.P. Preble
    JLab, Newport News, Virginia, USA
  • K.S. Smith, A. Zaltsman
    BNL, Upton, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under DOE Contract No. DE-SC0012704, by Jefferson Science Associates under contract DE-SC0002769, and by SLAC under Contract No. DE-AC02-76SF00515.
The Electron Ion Collider (EIC) to be constructed at Brookhaven National Laboratory in the USA will be a complex system of accelerators providing high luminosity, high polarization, variable center of mass energy collisions between electrons and protons or ions. To achieve this a variety of RF systems are required. They must provide for capture, formation and storage of Ampere-class beams in the electron and hadron storage rings (ESR and HSR), fast acceleration of high-charge polarized electron bunches in the rapid cycling synchrotron (RCS), provision of cold high current electron bunches in the high-energy cooler ERL and precise high-gradient crabbing of electrons and hadrons either side of the interaction point. The challenges include strong HOM damping in the storage ring cavities and cooler ERL, very high fundamental mode power in the ESR and cooler injector, extremely stable low-noise operation of the crab cavities, mitigation of transient beam loading from gaps, and operating over a wide range of energies and beam currents. We describe the high-level system parameters and principal design choices made and progress on the R&D plan to develop these state of the art systems. 		 
poster icon Poster MOPAB385 [1.268 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB385  
About • paper received ※ 18 May 2021       paper accepted ※ 31 May 2021       issue date ※ 30 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUXA03 Progress in Mastering Electron Clouds at the Large Hadron Collider simulation, electron, operation, experiment 1273
 
  • G. Iadarola, B. Bradu, L. Mether, K. Paraschou, V. Petit, G. Rumolo, L. Sabato, G. Skripka, M. Taborelli, L.J. Tavian
    CERN, Geneva, Switzerland
  • K. Paraschou
    AUTH, Thessaloniki, Greece
  
  During the second operational run of the Large Hadron Collider (LHC) a bunch spacing of 25 ns was used for the first time for luminosity production. With such a spacing, electron cloud effects are much more severe than with the 50-ns spacing, which had been used in the previous run. Beam-induced conditioning of the beam chambers mitigated the e-cloud formation to an extent that allowed an effective exploitation of 25 ns beams. Nevertheless, even after years of conditioning, e-cloud effects remained very visible, affecting beam stability and beam quality, and generating strong heat loads on the beam screens of the superconducting magnets with puzzling features. In preparation for the High Luminosity LHC upgrade, remarkable progress has been made in the modeling of the e-cloud formation and of its influence on beam stability, slow losses and emittance blow up, as well as in the understanding of the underlying behavior of the beam-chamber surface. In this contribution, we describe the main experimental observations from beam operation, the outcome of laboratory analysis conducted on beam screens extracted after the run, and the main advancements in the modeling of these phenomena.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUXA03  
About • paper received ※ 19 May 2021       paper accepted ※ 12 July 2021       issue date ※ 29 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPAB001 DAΦNE Commissioning for SIDDHARTA-2 Experiment optics, collider, feedback, positron 1322
 
  • C. Milardi, D. Alesini, O.R. Blanco-García, M. Boscolo, B. Buonomo, S. Cantarella, A. D’Uffizi, A. De Santis, C. Di Giulio, G. Di Pirro, A. Drago, L.G. Foggetta, G. Franzini, A. Gallo, S. Incremona, A. Michelotti, L. Pellegrino, L. Piersanti, R. Ricci, U. Rotundo, L. Sabbatini, A. Stecchi, A. Stella, A. Vannozzi, M. Zobov
    INFN/LNF, Frascati, Italy
  • J. Chavanne, G. Le Bec, P. Raimondi
    ESRF, Grenoble, France
  
  DAΦNE, the Frascati lepton collider, has completed the preparatory phase in order to deliver luminosity to the SIDDHARTA-2 detector. DAΦNE colliding rings rely on a new interaction region, which implements the well-established Crab-Waist collision scheme, and includes a low-beta section equipped with newly designed permanent magnet quadrupoles, and vacuum components. Diagnostics tools have been improved, especially the ones used to keep under control the beam-beam interaction. The horizontal feedback in the positron ring has been potentiated in order to achieve a higher positron current. Luminosity diagnostics have been also updated so to be compatible with the new detector design. The commissioning was initially focused on recovering the optimal dynamical vacuum conditions, outlining alignment errors, and optimizing ring optics. For this reason, a detuned optics, featured by relaxed low-b condition at the interaction point and Crab-Waist Sestupoles off, has been applied. In a second stage a low-b optics has been implemented to test collisions with a preliminary setup of the experiment detector. Machine preparation and the first luminosity results are presented and discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB001  
About • paper received ※ 19 May 2021       paper accepted ※ 09 June 2021       issue date ※ 10 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPAB002 Round Colliding Beams: Successful Operation Experience emittance, collider, solenoid, beam-beam-effects 1326
 
  • D.B. Shwartz, O.V. Belikov, D.E. Berkaev, D.B. Burenkov, V.S. Denisov, A.S. Kasaev, A.N. Kirpotin, S.A. Kladov, I. Koop, A.A. Krasnov, A.V. Kupurzhanov, G.Y. Kurkin, M.A. Lyalin, A.P. Lysenko, S.V. Motygin, E. Perevedentsev, V.P. Prosvetov, Yu.A. Rogovsky, A.M. Semenov, A.I. Senchenko, L.E. Serdakov, D.N. Shatilov, P.Yu. Shatunov, Y.M. Shatunov, M.V. Timoshenko, I.M. Zemlyansky, Yu.M. Zharinov
    BINP SB RAS, Novosibirsk, Russia
  • S.A. Kladov, I. Koop, A.A. Krasnov, M.A. Lyalin, E. Perevedentsev, Yu.A. Rogovsky, Y.M. Shatunov, D.B. Shwartz
    NSU, Novosibirsk, Russia
  
  VEPP-2000 electron-positron collider operating in the beam energy range of 150-1000 MeV is the only machine originally designed for and successfully exploiting Round Beams Concept. After injection chain upgrade including link to the new BINP injection complex VEPP-2000 proceeded with data taking since 2017 with luminosity limited only by beam-beam effects. At the low energies (300-600 MeV/beam) the novel technique of effective emittance controlled increase by weak coherent beam shaking allowed to suppress the limiting flip-flop effect and resulted in additional luminosity gain factor of 4. The averaged delivered luminosity at the omega-meson production energy (2*391 MeV) achieved L = 2*1031cm-2s−1/IP. At the top energies above nucleon-antinucleon production threshold the stable operation with luminosity of L = 5*1031cm-2s−1/IP resulted in high average data taking rate of 2 pb-1/day in 2020.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB002  
About • paper received ※ 20 May 2021       paper accepted ※ 07 June 2021       issue date ※ 31 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPAB013 A CLIC Dual Beam Delivery System for Two Interaction Regions solenoid, detector, collider, linear-collider 1364
 
  • V. Cilento, R. Tomás García
    CERN, Geneva, Switzerland
  • A. Faus-Golfe
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  
  The Compact Linear Collider (CLIC) could provide e+e− collisions in two detectors simultaneously possibly at a repetition frequency twice the design value. In this paper, a novel dual Beam Delivery System (BDS) design is presented including optics designs and the evaluation of luminosity performance with synchrotron radiation (SR) and solenoid effects for both energy stages of CLIC, 380 GeV and 3 TeV. In order to develop the novel optics design, parameters such as the longitudinal and the transverse detector separations were optimized. The luminosity performance of the novel CLIC scheme was evaluated by comparing the different BDS designs for both energy stages of CLIC. The dual CLIC BDS design provides a good luminosity and proves to be a viable candidate for future linear collider projects.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB013  
About • paper received ※ 17 May 2021       paper accepted ※ 09 June 2021       issue date ※ 31 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPAB027 Review of Accelerator Limitations and Routes to Ultimate Beams collider, acceleration, electron, photon 1397
 
  • F. Zimmermann
    CERN, Geneva, Switzerland
  • R.W. Aßmann
    DESY, Hamburg, Germany
  • M. Bai, G. Franchetti
    GSI, Darmstadt, Germany
  
  Funding: This work was supported in part by the European Commission under the HORIZON 2020 project I.FAST, no. 101004730.
Various physical and technology-dependent limits are encountered for key performance parameters of accelerators such as high-gradient acceleration, high-field bending, beam size, beam brightness, beam intensity and luminosity. This paper will review these limits and the associated challenges. Possible figures-of-merit and pathways to ultimate colliders will also be explored. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB027  
About • paper received ※ 16 May 2021       paper accepted ※ 02 August 2021       issue date ※ 23 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEXA01 Successful Crabbing of Proton Beams cavity, collider, emittance, impedance 2510
 
  • R. Calaga
    CERN, Meyrin, Switzerland
  
  Funding: Research supported by the HL-LHC project and by the DOE and UK-STFC.
Many future particle colliders require beam crabbing to recover the geometric luminosity loss from the non-zero crossing angle at the interaction point. A first demonstration experiment of crabbing with hadron beams was successfully carried out with high energy protons. This breakthrough result is fundamental to achieve the physics goals of the high luminosity LHC upgrade project (HL-LHC) and the future circular collider (FCC). The expected peak luminosity gain (related to collision rate) is 65% for HL-LHC, and even greater for the FCC. Novel beam physics experiments with proton beams in CERN’s Super Proton Synchrotron (SPS) were performed to demonstrate several critical aspects for the operation of crab cavities in the future HL-LHC including transparency with a pair of cavities, a full characterization of the cavity impedance with high beam currents and controlled emittance growth from crab cavity induced RF noise. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXA01  
About • paper received ※ 14 May 2021       paper accepted ※ 28 July 2021       issue date ※ 24 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEXA05 Solving for Collider Beam Profiles from Luminosity Jitter with Ghost Imaging collider, operation, GUI, diagnostics 2524
 
  • D.F. Ratner, A. Chao
    SLAC, Menlo Park, California, USA
  
  Large accelerator facilities must balance the need to achieve user performance requirements while also maximizing delivery time. At the same time, accelerators have advanced data-acquisition systems that acquire synchronous data at high-rate from a large variety of diagnostics. Here we discuss the application of ghost-imaging (GI) to measure beam parameters, switching the emphasis from beam control to data collection: rather than intentionally manipulating the accelerator, we instead passively monitor jitter gathered over thousands to millions of events to reconstruct the target of interest. Passive monitoring during routine operation builds large data sets that can even deliver higher resolution than brief periodic scans, and can provide experiments with event-by-event information. In this presentation we briefly present applications of GI to light-sources, and then discuss a potential new application for colliders: measuring the transverse beam shapes at a collider’s interaction point to determine both the integrated luminosity and the spatial distribution of collision vertices.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXA05  
About • paper received ※ 19 May 2021       paper accepted ※ 27 July 2021       issue date ※ 10 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEXA06 Study of Pb-Pb and Pb-p Collision Debris in the CERN LHC in View of HL-LHC Operation operation, proton, hadron, heavy-ion 2528
 
  • M. Sabaté-Gilarte, R. Bruce, F. Cerutti, A. Lechner
    CERN, Meyrin, Switzerland
  
  Funding: Research supported by the HL-LHC project
For the first time, a full characterization of the Pb-Pb and Pb-p collision debris as well as its impact in terms of energy deposition in the long straight section (LSS) of CERN’s Large Hadron Collider has been carried out. By means of Monte Carlo simulations with FLUKA, both inelastic nuclear interaction and electromagnetic dissociation were taken into account as source term for lead ion operation, while for Pb-p operation only nuclear interaction is of importance. The radiation exposure of detectors exclusively destined for ion beam runs is assessed, allowing drawing implications of their use. This work gave the opportunity for an unprecedented validation of simulation results against measurement of beam loss monitors (BLM) in the experimental LSS during ion operation. Pb-Pb operation refers to the 2018 ion run at 6.37 TeV per charge with a +160 microrad half crossing angle in the vertical plane at the ATLAS interaction point. Instead, Pb-p operation was benchmarked for the 2016 ion run at 6.5 TeV per charge with -140 microrad half crossing angle in the vertical plane at the same location. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXA06  
About • paper received ※ 18 May 2021       paper accepted ※ 05 July 2021       issue date ※ 22 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEXA07 Beam Background Measurements at SuperKEKB/Belle-II in 2020 background, injection, detector, scattering 2532
 
  • H.N. Nakayama, T. Koga
    KEK, Ibaraki, Japan
  • K. Kojima
    Nagoya University, Nagoya, Japan
  • A. Natochii, S. Vahsen
    University of Hawaii, Honolulu,, USA
  
  The SuperKEKB electron-positron collider began collision operation in 2018 and achieved the world-record luminosity of 2.4x1034~cm-2s-1 in June 2020. We pursue higher luminosity by squeezing beam sizes and increasing beam currents. Beam backgrounds induced by stray particles will also increase and might cause severe radiation damage to Belle II detector components and worsen the quality of collected physics data. To mitigate these backgrounds, we have carefully designed our interaction region and installed movable collimators in the machine. We present recent measurements of beam background at SuperKEKB. We have performed dedicated machine studies to measure each background component separately and found that beam-gas scattering and Touschek scattering in the positron ring are the dominant sources of background rates in Belle II. We also present the latest observations of injection background, which determines the timing of a required Belle II data acquisition trigger veto and therefore affects the integrated luminosity. We show the beam background extrapolation toward the expected higher-luminosity operation and our plans for further background mitigation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXA07  
About • paper received ※ 20 May 2021       paper accepted ※ 25 June 2021       issue date ※ 13 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPAB004 Electron-Ion Luminosity Maximization in the EIC electron, collider, emittance, hadron 2582
 
  • W. Fischer, E.C. Aschenauer, M. Blaskiewicz, K.A. Drees, A.V. Fedotov, H. Huang, C. Montag, V. Ptitsyn, D. Raparia, V. Schoefer, K.S. Smith, P. Thieberger, F.J. Willeke
    BNL, Upton, New York, USA
  • Y. Zhang
    JLab, Newport News, Virginia, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
The electron-ion luminosity in EIC has a number of limits, including the ion intensity available from the injectors, the total ion beam current, the electron bunch intensity, the total electron current, the synchrotron radiation power, the beam-beam effect, the achievable beta functions at the interaction points (IPs), the maximum angular spreads at the IP, the ion emittances reachable with stochastic or strong cooling, the ratio of horizontal to vertical emittance, and space charge effects. We map the e-A luminosity over the center-of-mass energy range for some ions ranging from deuterons to uranium ions. For e-Au collisions the present design provides for electron-nucleon (e-Au) peak luminosities of 1.7x1033 cm-2s−1 with stochastic cooling, and 4.7x1033 cm-2s−1 with strong hadron cooling. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB004  
About • paper received ※ 18 May 2021       paper accepted ※ 21 June 2021       issue date ※ 20 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPAB016 Snowmass’21 Accelerator Frontier collider, hadron, target, electron 2621
 
  • V.D. Shiltsev
    Fermilab, Batavia, Illinois, USA
  • S.A. Gourlay
    LBNL, Berkeley, California, USA
  • T.O. Raubenheimer
    SLAC, Menlo Park, California, USA
  
  Snowmass’21 is decadal particle physics community planning study. It provides an opportunity for the entire particle physics community to come together to identify and document a scientific vision for the future of particle physics in the U.S. and its international partners. Snowmass will define the most important questions for the field of particle physics and identify promising opportunities to address them. The P5, Particle Physics Project Prioritization Panel, will take the scientific input from Snowmass and develop a strategic plan for U.S. particle physics that can be executed over a 10 year timescale, in the context of a 20-year global vision for the field. Here we present the goals, progress and plans of the Snowmass’21 Accelerator Frontier.  
poster icon Poster WEPAB016 [1.108 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB016  
About • paper received ※ 17 May 2021       paper accepted ※ 23 June 2021       issue date ※ 12 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPAB017 General Approach to Physics Limits of Ultimate Colliders collider, acceleration, plasma, radiation 2624
 
  • V.D. Shiltsev
    Fermilab, Batavia, Illinois, USA
  
  The future of the particle physics is critically dependent on feasibility of future energy frontier colliders. The concept of the feasibility is complex and includes at least three factors: feasibility of energy, feasibility of luminosity, and feasibility of cost and construction time. Here we discuss major beam physics limits of ultimate accelerators, take a look into ultimate energy reach of possible future colliders. We also foresee a looming paradigm change for the HEP research as the thrust for higher energies by necessity will mean lower luminosity.  
poster icon Poster WEPAB017 [1.720 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB017  
About • paper received ※ 19 May 2021       paper accepted ※ 24 June 2021       issue date ※ 17 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPAB023 Crystal Collimation of 20 MJ Heavy-Ion Beams at the HL-LHC collimation, operation, hadron, collider 2644
 
  • M. D’Andrea, R. Bruce, M. Di Castro, I. Lamas Garcia, A. Masi, D. Mirarchi, S. Redaelli, R. Rossi, B. Salvachua, W. Scandale
    CERN, Geneva, Switzerland
  • F. Galluccio
    INFN-Napoli, Napoli, Italy
  • L.J. Nevay
    Royal Holloway, University of London, Surrey, United Kingdom
  
  The concept of crystal collimation at the Large Hadron Collider (LHC) relies on the use of bent crystals that can deflect halo particles by a much larger angle than the standard multi-stage collimation system. Following an extensive campaign of studies and performance validations, a number of crystal collimation tests with Pb ion beams were performed in 2018 at energies up to 6.37 Z TeV. This paper describes the procedure and outcomes of these tests, the most important of which being the demonstration of the capability of crystal collimation to improve the cleaning efficiency of the machine. These results led to the inclusion of crystal collimation into the LHC baseline for operation with ion beams in Run 3 as well as for the HL-LHC era. A first set of operational settings was defined.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB023  
About • paper received ※ 19 May 2021       paper accepted ※ 23 June 2021       issue date ※ 27 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPAB026 Optics Measurements and Correction Plans for the HL-LHC coupling, optics, dynamic-aperture, dipole 2656
 
  • T.H.B. Persson, X. Buffat, F.S. Carlier, R. De Maria, J. Dilly, E. Fol, D. Gamba, H. Garcia Morales, A. García-Tabarés Valdivieso, M. Giovannozzi, M. Hofer, E.J. Høydalsvik, J. Keintzel, M. Le Garrec, E.H. Maclean, L. Malina, P.K. Skowroński, F. Soubelet, R. Tomás García, F.F. Van der Veken, A. Wegscheider, D.W. Wolf, L. van Riesen-Haupt
    CERN, Geneva, Switzerland
  • J.M. Coello de Portugal
    PSI, Villigen PSI, Switzerland
  
  The High Luminosity LHC (HL-LHC) will require stringent optics correction to operate safely and deliver the design luminosity to the experiments. In order to achieve this, several new methods for optics correction have been developed. In this article, we outline some of these methods and we describe the envisioned strategy of how to use them in order to reach the challenging requirements of the HL-LHC physics program.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB026  
About • paper received ※ 17 May 2021       paper accepted ※ 27 July 2021       issue date ※ 30 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPAB033 Lattice Design of the CEPC Collider Ring for a High Luminosity Scheme collider, lattice, dynamic-aperture, quadrupole 2679
 
  • Y. Wang, S. Bai, J. Gao, B. Wang, D. Wang, Y. Wei, J. Wu, C.H. Yu, J.Y. Zhai, Y. Zhang, Y.S. Zhu
    IHEP, Beijing, People’s Republic of China
  • Y. Zhang
    University of Chinese Academy of Sciences, Beijing, People’s Republic of China
  
  A high luminosity scheme of the CEPC has been proposed aiming to increase the luminosity mainly at Higgs and Z modes. In this paper, the high luminosity scheme will be introduced briefly, including the beam parameters and RF staging. Then, the lattice design of the CEPC collider ring for the high luminosity scheme will be presented, including the bare lattice design and dynamic aperture optimization at Higgs energy.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB033  
About • paper received ※ 20 May 2021       paper accepted ※ 05 July 2021       issue date ※ 27 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPAB278 Beam-Beam Simulations for Lepton-Hadron Colliders: ALOHEP Software collider, hadron, lepton, linac 3293
 
  • B.B. Oner
    Gazi University, Faculty of Arts and Sciences, Teknikokullar, Ankara, Turkey
  • B. Dagli, S. Sultansoy
    TOBB ETU, Ankara, Turkey
  • B. Ketenoğlu
    Ankara University, Faculty of Engineering, Tandogan, Ankara, Turkey
  
  It is known that rough luminosity estimations for ll, lh, and hh colliders can be performed easily using nominal beam parameters. In principle, more precise results can be obtained by analytical solutions. However, beam dynamics is usually neglected in this case since it is almost impossible to cope with beam size fluctuations. In this respect, several beam-beam simulation programs for linear e+e− and photon colliders have been proposed while no similar open-access simulation exists for all types of colliders (i.e. linac-ring ep colliders). Here, we present the software ALOHEP (A Luminosity Optimizer for High Energy Physics), a luminosity calculator for linac-ring and ring-ring lh colliders, which also computes IP parameters such as beam-beam tune shift, disruption arising out of electromagnetic interactions. In addition, the program allows taking crossing-angle effects on luminosity into account.
* Y.C. Acar et al., Nucl. Instrum. Meth. A, 871 (2017). 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB278  
About • paper received ※ 19 May 2021       paper accepted ※ 26 July 2021       issue date ※ 27 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPAB280 Two-Dimensional Beam-Beam Invariant with Applications to HL-LHC optics, resonance, closed-orbit, lattice 3301
 
  • D. Kaltchev
    TRIUMF, Vancouver, Canada
  
  Long-range beam-beam interactions represent the most severe limitation on the performance and achievable luminosity of circular collider. The paper presents a two-dimensional nonlinear Courant Snyder Invariant derived to first order in the beam-beam perturbation and based on the two-dimensional coefficients in the Fourier expansion of the Beam-beam Hamiltonian. Its validity in case of HL-LHC lattices with realistic beam-beam setup is verified with MadX tracking.  
poster icon Poster WEPAB280 [1.235 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB280  
About • paper received ※ 14 May 2021       paper accepted ※ 06 July 2021       issue date ※ 12 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPAB281 The Precision Laser Inclinometer laser, experiment, detector, operation 3305
 
  • B. Di Girolamo, S. Vlachos
    CERN, Geneva, Switzerland
  • Ju. Boudagov, M.V. Lyablin
    JINR, Dubna, Moscow Region, Russia
  
  Earth surface movements, like earthquakes or human-produced (cultural) noise, can induce a degradation of the instantaneous luminosity of particle accelerators or even sudden beam losses. In the same way the presence of seismic and cultural noise limits the detection capabilities of interferometric antennas used for the observations of gravitational waves. This contribution discusses the importance of monitoring the effects of earth vibrations using a novel multi-purpose instrument, the Precision Laser Inclinometer (PLI). Few examples of recorded events are discussed along with ideas on PLI applications.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB281  
About • paper received ※ 16 May 2021       paper accepted ※ 01 July 2021       issue date ※ 12 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPAB015 Studies of the Imperfection in Crab Crossing Scheme for Electron-Ion Collider cavity, electron, solenoid, proton 3784
 
  • Y. Hao, J.S. Berg, D. Holmes, Y. Luo, C. Montag
    BNL, Upton, New York, USA
  • V.S. Morozov
    JLab, Newport News, Virginia, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
  • D. Xu
    FRIB, East Lansing, Michigan, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
Crab crossing scheme is the essential scheme that accommodates large crossing angle without loss of luminosity in the design of Electron-Ion collider (EIC). The ideal optics and phase advances of the crab cavity pair are set to create a local crabbing bump in the interaction region (IR). However, there are always small errors in the actual lattice of IR. In this article, we will present the simulation and analytical studies on the imperfections in the crab crossing scheme in the EIC design. The tolerance of the imperfection and the possible remedies can be concluded from these studies. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB015  
About • paper received ※ 17 May 2021       paper accepted ※ 16 July 2021       issue date ※ 12 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPAB017 The International Muon Collider Collaboration collider, emittance, target, radiation 3792
 
  • D. Schulte
    CERN, Meyrin, Switzerland
  
  A muon collider offers a unique opportunity for high-energy, high-luminosity lepton collisions and could push the frontiers of particle physics by providing excellent discovery reach with excellent precision. A scheme has been developed by the MAP collaboration. The updated European Strategy for Particle Physics recommended the development of an Accelerator R&D Roadmap for Europe and CERN Council has charged the LDG to develop it. LDG has initiated panels to provide input including one on the use of muon beams, in particular in view of a high-energy, high luminosity muon collider. A new international collaboration, is forming to develop a muon collider design and address the associated challenges, which are mainly due to the limited muon lifetime. The focus is on two energy ranges, around 3 TeV and above 10 TeV. Ambitious magnets, RF systems, targets and shielding are key for the design.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB017  
About • paper received ※ 19 May 2021       paper accepted ※ 26 July 2021       issue date ※ 11 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPAB028 Beam-Beam Related Design Parameter Optimization for the Electron-Ion Collider proton, electron, simulation, betatron 3808
 
  • Y. Luo, J.S. Berg, M. Blaskiewicz, W. Fischer, X. Gu, H. Lovelace III, C. Montag, R.B. Palmer, S. Peggs, V. Ptitsyn, F.J. Willeke
    BNL, Upton, New York, USA
  • Y. Hao, D. Xu
    FRIB, East Lansing, Michigan, USA
  • H. Huang
    ODU, Norfolk, Virginia, USA
  • E.A. Nissen, T. Satogata
    JLab, Newport News, Virginia, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The design luminosity goal for the Electron-Ion Collider (EIC) is 1e34 cm-2s−1. To achieve such a high luminosity, the EIC design adopts high bunch intensities, flat beams at the interaction point (IP) with a small vertical β*-function, and a high collision frequency, together with crab cavities to compensate the geometrical luminosity loss due to the large crossing angle of 25mrad. In this article, we present our strategies and approaches to obtain the design luminosity by optimizing some key beam-beam related design parameters. Through our extensive strong-strong and weak-strong beam-beam simulations, we found that beam flatness, electron and proton beam size matching at the IP, electron and proton working points, and synchro-betatron resonances arising from the crossing angle collision play a crucial role in proton beam size growth and luminosity degradation. After optimizing those parameters, we found a set of beam-beam related design parameters to reach the design luminosity with an acceptable beam-beam performance. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB028  
About • paper received ※ 17 May 2021       paper accepted ※ 28 July 2021       issue date ※ 25 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPAB172 Bunch Luminosity Variations in LHC Run 2 emittance, injection, experiment, operation 4094
 
  • I. Efthymiopoulos, S.D. Fartoukh, G. Iadarola, N. Karastathis, S. Papadopoulou, Y. Papaphilippou
    CERN, Geneva, Switzerland
  
  The LHC is designed to collide intense bunches of protons with tightly defined conditions, aimed to maximize the delivered recorded integrated luminosity to the experiments. One of these conditions is the maximum level of bunch-to-bunch fluctuation in the luminosity, in particular when levelling at maximum acceptable event rate at the experiments. Analysis results of the bunch-to-bunch luminosity variations in LHC Run 2 are presented here. In particular, the observed correlations with the LHC filling pattern that can enhance the effects introducing bunch-dependent losses or emittance blow-up from injection to collisions are discussed. In Run 2 conditions, bunch-by-bunch luminosity fluctuations reached 10% at the start of collisions and gradually increased with time, without affecting the experiments as the luminosity was not levelled. Projections for Run 3 and HL-LHC operation are discussed along with envisaged mitigation measures.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB172  
About • paper received ※ 18 May 2021       paper accepted ※ 19 July 2021       issue date ※ 23 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)