Author: Dilly, J.
Paper Title Page
MOPAB258 Corrections of Non-Linear Field Errors with Asymmetric Optics in LHC and HL-LHC Insertion Regions 817
 
  • J. Dilly, E.H. Maclean, R. Tomás García
    CERN, Geneva, Switzerland
  
  Funding: Research supported by the HL-LHC project, CERN and the german Federal Ministry of Education and Research.
Existing correction schemes to locally suppress resonance driving terms in the error-sensitive high-beta regions of the LHC and HL-LHC have operated on the assumption of symmetric beta-functions of the optics in the two rings. As this assumption can fail for a multitude of reasons, such as inherently asymmetric optics and unevenly distributed errors, an extension of this correction scheme has been developed removing the need for symmetry by operating on the two separate optics of the beams at the same time. Presented here is the impact of this novel approach on dynamic aperture as an important measure of particle stability. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB258  
About • paper received ※ 10 May 2021       paper accepted ※ 23 July 2021       issue date ※ 16 August 2021  
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MOPAB259 Corrections of Feed-Down of Non-Linear Field Errors in LHC and HL-LHC Insertion Regions 821
 
  • J. Dilly, E.H. Maclean, R. Tomás García
    CERN, Geneva, Switzerland
  
  Funding: Research supported by the HL-LHC project, CERN and the german Federal Ministry of Education and Research.
The optics in the insertion regions of the LHC and its upgrade project the High Luminosity LHC (HL-LHC) are very sensitive to local magnetic errors, due to the extremely high beta-functions present. In collision optics, the non-zero closed orbit in the same region leads to a "feed-down" of high-order errors to lower orders, causing additional effects detrimental to beam lifetime. An extension to the proven method for correcting these errors by locally suppressing resonance driving terms has been undertaken, not only taking this feed-down into account, but also adding the possibility of utilizing it such that the powering of higher-order correctors will compensate for lower order errors. The impact of these corrections on measures of particle stability, namely dynamic aperture and amplitude detuning are presented in this contribution. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB259  
About • paper received ※ 10 May 2021       paper accepted ※ 23 July 2021       issue date ※ 15 August 2021  
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WEPAB026 Optics Measurements and Correction Plans for the HL-LHC 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, Meyrin, 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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WEPAB027 Optics Correction Strategy for Run 3 of the LHC 2660
 
  • T.H.B. Persson, R. De Maria, J. Dilly, E. Fol, H. Garcia Morales, M. Hofer, E.J. Høydalsvik, J. Keintzel, M. Le Garrec, E.H. Maclean, L. Malina, F. Soubelet, R. Tomás García, A. Wegscheider, D.W. Wolf, L. van Riesen-Haupt
    CERN, Meyrin, Switzerland
  • J.F. Cardona
    UNAL, Bogota D.C, Colombia
  
  The Run 3 of the LHC will continue to provide new challenges for optics corrections. In order to succeed and go beyond what was achieved previously, several new methods to measure and correct the optics have been developed. In this article we describe these methods and outline the plans for the optics commissioning in 2022.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB027  
About • paper received ※ 17 May 2021       paper accepted ※ 12 July 2021       issue date ※ 11 August 2021  
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THPAB168 Optics Measurement by Excitation of Betatron Oscillations in the CERN PSB 4078
 
  • E.H. Maclean, F. Antoniou, F. Asvesta, H. Bartosik, C. Bracco, J. Dilly, E. Fol, H. Garcia Morales, M. Hofer, J. Keintzel, M. Le Garrec, T.E. Levens, L. Malina, T.H.B. Persson, T. Prebibaj, E. Renner, P.K. Skowroński, F. Soubelet, R. Tomás García, A. Wegscheider, L. van Riesen-Haupt
    CERN, Meyrin, Switzerland
  
  Optics measurement from analysis of turn-by-turn BPM data of betatron oscillations excited with a kicker magnet has been employed very successfully in many machines but faces particular challenges in the CERN PSB where BPM to BPM phase advances are sub-optimal for optics reconstruction. Experience using turn-by-turn oscillation data for linear optics measurements during PSB commissioning in2021 is presented, with implications for the prospect of such techniques in the PSB more generally.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB168  
About • paper received ※ 19 May 2021       paper accepted ※ 14 July 2021       issue date ※ 27 August 2021  
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