Keyword: luminosity
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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.  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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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  
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