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Optics for Landau Damping with Minimized Octupolar Resonances in the LHC
/ Wenninger, J (CERN) ; Solfaroli, M (CERN) ; Nissinen, T (CERN) ; Hostettler, M (CERN) ; Horney, S (CERN) ; Chudoba, F (CERN) ; Tomás García, Rogelio (CERN) ; Carlier, Felix (CERN) ; Deniau, Laurent (CERN) ; Dilly, Joschua (CERN) et al.
Operation of the Large Hadron Collider (LHC) requires strong octupolar magnetic fields to suppress coherent beam instabilities. The amplitude detuning that is generated by these octupolar magnetic fields brings the tune of individual particles close to harmful resonances, which are mostly driven by the octupolar fields themselves. [...]
2024 - 4 p.
- Published in : JACoW HB 2023 (2024) 503-506
Fulltext: PDF;
In : 68th ICFA Advanced Beam Dynamics workshop on high-Intensity and High-Brightness Hadron Beams (HB 2023), CERN, Geneva, Switzerland, 9 - 13 Oct 2023, pp.503-506
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Optics Correction Strategy for Run 3 of the LHC
/ Persson, Tobias (CERN) ; Cardona, Javier (Colombia, U. Natl.) ; De Maria, Riccardo (CERN) ; Dilly, Joschua (CERN) ; Fol, Elena (CERN) ; Garcia Morales, Hector (CERN) ; Hofer, Michael (CERN) ; Høydalsvik, Eirik (CERN) ; Keintzel, Jacqueline (CERN) ; Le Garrec, Mael (CERN) et al.
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. [...]
JACoW, 2021 - 4 p.
- Published in : JACoW IPAC 2021 (2021) WEPAB027
Fulltext: PDF;
In : 12th International Particle Accelerator Conference (IPAC 2021), Online, 24 - 28 May 2021, pp.WEPAB027
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3.
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Experimental Demonstration of Machine Learning Application in LHC Optics Commissioning
/ Fol, Elena (CERN) ; Cardona, Javier (Colombia, U. Natl.) ; Carlier, Felix (CERN) ; Dilly, Joschua (CERN) ; Hofer, Michael (CERN) ; Keintzel, Jacqueline (CERN) ; Le Garrec, Mael (CERN) ; Maclean, Ewen (CERN) ; Persson, Tobias (CERN) ; Soubelet, Felix (CERN) et al.
Recently, we conducted successful studies on the suitability of machine learning (ML) methods for optics measurements and corrections, incorporating novel ML-based methods for local optics corrections and reconstruction of optics functions. After performing extensive verifications on simulations and past measurement data, the newly developed techniques became operational in the LHC commissioning 2022. [...]
2022 - 4 p.
- Published in : JACoW IPAC 2022 (2022) 359-362
Fulltext: PDF;
In : 13th International Particle Accelerator Conference (IPAC 2022), Bangkok, Thailand, 12 - 17 Jun 2022, pp.359-362
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Optimizing Resonance Driving Terms Using MAD-NG Parametric Maps
/ Deniau, Laurent (CERN) ; Kostoglou, Sofia (CERN) ; Maclean, Ewen (CERN) ; Paraschou, Konstantinos (CERN) ; Persson, Tobias (CERN) ; Tomás García, Rogelio (CERN)
In 2023, a review of the LHC octupolar resonance driving terms at injection was carried out, motivated by two observations: (i) unwanted losses during the injection process with strongly powered octupoles and (ii) an expected reduction in emittance growth from e-cloud effects in simulations with weaker octupolar resonances. The MAD-NG code was used to simultaneously optimise the main octupolar resonances: 4Qx, 4Qy, and 2Qx-2Qy by adjusting 16 quadrupole families and 16 octupole families, for a total of 32 parameters. [...]
2024 - 4 p.
- Published in : JACoW HB 2023 (2024) 483-486
Fulltext: PDF;
In : 68th ICFA Advanced Beam Dynamics workshop on high-Intensity and High-Brightness Hadron Beams (HB 2023), CERN, Geneva, Switzerland, 9 - 13 Oct 2023, pp.483-486
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Optics Measurement by Excitation of Betatron Oscillations in the CERN PSB
/ Maclean, Ewen H (CERN) ; Antoniou, Fanouria (CERN) ; Asvesta, Foteini (CERN) ; Bartosik, Hannes (CERN) ; Bracco, Chiara (CERN) ; Dilly, Joschua W (CERN) ; Fol, Elena (CERN) ; Garcia Morales, Hector (CERN) ; Hofer, Michael (CERN) ; Keintzel, Jacqueline (CERN) et al.
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..
Geneva : JACoW, 2021 - 4 p.
- Published in : JACoW IPAC '21 (2021) 4078-4081
Fulltext: PDF;
In : 12th International Particle Accelerator Conference (IPAC 2021), Online, 24 - 28 May 2021, pp.4078-4081
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6.
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Optics Measurements and Correction Plans for the HL-LHC
/ Persson, Tobias (CERN) ; Buffat, Xavier (CERN) ; Carlier, Felix (CERN) ; Coello de Portugal, Jaime Maria (PSI, Villigen) ; De Maria, Riccardo (CERN) ; Dilly, Joschua (CERN) ; Fol, Elena (CERN) ; Gamba, Davide (CERN) ; Garcia Morales, Hector (CERN) ; García-Tabarés Valdivieso, Ana (CERN) et al.
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. [...]
2021 - 4 p.
- Published in : 10.18429/JACoW-IPAC2021-WEPAB026
Fulltext: PDF;
In : 12th International Particle Accelerator Conference (IPAC 2021), Online, Br, 24 - 28 May 2021, pp.2656-2659
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7.
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Optics Correction Strategy for Run 3 of the LHC
/ Persson, Tobias (CERN) ; Cardona, Javier (Colombia, U. Natl.) ; Carlier, Felix (CERN) ; Costa Ojeda, Andressa (CERN) ; Dilly, Joschua (CERN) ; Ferrentino, Vittorio (CERN) ; Fol, Elena (CERN) ; García Morales, Hector (CERN) ; Hofer, Michael (CERN) ; Høydalsvik, Eirik (CERN) et al.
After more than 3 years of shutdown the LHC is again operational in 2022. Experience from the previous Long Shutdown (LS) has shown that the local errors in the triplet quadrupoles changed significantly between Run 1 and Run 2, and first measurements in 2022 unveil further changes. [...]
2022 - 4 p.
- Published in : JACoW IPAC 2022 (2022) 1687-1690
Fulltext: PDF;
In : 13th International Particle Accelerator Conference (IPAC 2022), Bangkok, Thailand, 12 - 17 Jun 2022, pp.1687-1690
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8.
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LHC Optics Measurements from Transverse Damper for the High Intensity Frontier
/ Nissinen, Tuuli (CERN) ; Carlier, Felix (CERN) ; Le Garrec, Mael (CERN) ; Maclean, Ewen (CERN) ; Persson, Tobias (CERN) ; Tomás García, Rogelio (CERN) ; Wegscheider, Andreas (CERN)
Current and future accelerator projects are pushing the brightness and intensity frontier, creating new challenges for turn-by-turn based optics measurements. Transverse oscillations are limited in amplitude due to particle losses. [...]
2024 - 4 p.
- Published in : JACoW HB 2023 (2024) 479-482
Fulltext: PDF;
In : 68th ICFA Advanced Beam Dynamics workshop on high-Intensity and High-Brightness Hadron Beams (HB 2023), CERN, Geneva, Switzerland, 9 - 13 Oct 2023, pp.479-482
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Analysis on bunch-by-bunch beam losses at 6.5 TeV in the Large Hadron Collider
/ Paraschou, Konstantinos (CERN ; Aristotle U., Thessaloniki) ; Iadarola, Giovanni (CERN) ; Karastathis, Nikolaos (CERN) ; Kostoglou, Sofia (Natl. Tech. U., Athens ; CERN) ; Papaphilippou, Yannis (CERN) ; Sabato, Luca (CERN)
In 2018, a large fraction of the physics data taking at the Large Hadron Collider has been performed with a beam energy of 6.5 TeV, the nominal bunch spacing of 25 ns and beta functions at the high luminosity interaction points of 30 cm. In order to maximize the integrated luminosity, the crossing angles are gradually reduced as the beam intensity reduces due to luminosity burn-off. [...]
CERN-ACC-2019-068.-
2019 - 4 p.
- Published in : 10.18429/JACoW-IPAC2019-MOPMP029
Fulltext from publisher: PDF;
In : 10th International Particle Accelerator Conference, Melbourne, Australia, 19 - 24 May 2019, pp.MOPMP029
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10.
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Emittance Growth From Electron Clouds Forming in the LHC Arc Quadrupoles
/ Paraschou, Konstantinos (CERN) ; Bartosik, Hannes (CERN) ; Deniau, Laurent (CERN) ; Iadarola, Giovanni (CERN) ; Maclean, Ewen (CERN) ; Mether, Lotta (CERN) ; Papaphilippou, Yannis (CERN) ; Pieloni, Tatiana (Ecole Polytechnique, Lausanne) ; Potdevin, Joséphine (Ecole Polytechnique, Lausanne) ; Rumolo, Giovanni (CERN) et al.
Operation of the Large Hadron Collider with proton bunches spaced 25 ns apart favours the formation of electron clouds. In fact, a slow emittance growth is observed in proton bunches at injection energy (450 GeV), showing a bunch-by-bunch signature that is compatible with electron cloud effects. [...]
2024 - 4 p.
- Published in : JACoW HB 2023 (2024) 487-490
Fulltext: PDF;
In : 68th ICFA Advanced Beam Dynamics workshop on high-Intensity and High-Brightness Hadron Beams (HB 2023), CERN, Geneva, Switzerland, 9 - 13 Oct 2023, pp.487-490
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