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Impedance and thermal studies of the CERN SPS wire scanners and mitigation of wire heating
/ de la Fuente, Elena (CERN) ; Papazoglou, I (CERN) ; Sito, Leonardo (CERN) ; Andreazza, William (CERN) ; Antuono, Chiara (CERN) ; Bruchon, N (CERN) ; Calaga, Rama (CERN) ; Carra, Federico (CERN) ; Emery, J (CERN) ; Harrison, Anthony (CERN) et al.
All wires of the four CERN SPS rotational wirescanners broke when increasing the beam intensity towards the target for the LHC Injector Upgrade in 2023. Impedance and thermal studies were immediately launched, with simulations and measurements indicating that beam induced heating from resonant modes on the thin wire could be sufficient to cause these breakages. [...]
2024 - 4 p.
- Published in : JACoW IPAC 2024 (2024) WEPG29
Fulltext: PDF;
In : 15th International Particle Accelerator Conference (IPAC 2024), Nashville, TN, United States, 19 - 24 May 2024, pp.WEPG29
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Overview of beam intensity issues and mitigations in the CERN-SPS fast wire scanners
/ Veness, Raymond (CERN) ; Guerrero, Ana (CERN) ; Perez Fontenla, Ana Teresa (CERN) ; Harrison, Anthony (CERN) ; Salvant, Benoit (CERN) ; Zannini, Carlo (CERN) ; Antuono, Chiara (CERN) ; Vollinger, Christine (CERN) ; de la Fuente, Elena (CERN) ; Carra, Federico (CERN) et al.
A new design of fast wire scanner was installed in the CERN injector complex as part of the upgrades linked to the High-Luminosity LHC Project. Initial operations with these beams were good, but during the planned intensity ramp-up one early 2023, all four SPS scanners failed at the same time. [...]
2024 - 4 p.
- Published in : JACoW IPAC 2024 (2024) WEPG26
Fulltext: PDF;
In : 15th International Particle Accelerator Conference (IPAC 2024), Nashville, TN, United States, 19 - 24 May 2024, pp.WEPG26
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3.
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Beam Performance with the LHC Injectors Upgrade
/ zannini, C (CERN) ; Wegner, R (CERN) ; Vollinger, C (CERN) ; Veness, R (CERN) ; Velotti, F (CERN) ; Sullivan, M (CERN) ; Steerenberg, R (CERN) ; Spierer, A (CERN) ; Skowronski, P (CERN) ; Sito, L (CERN) et al.
The LHC Injectors Upgrade (LIU) project was put in place between 2010 and 2021 to increase the intensity and brightness in the LHC injectors to match the challenging requirements of the High-Luminosity LHC (HL-LHC) project, while ensuring reliable operation of the injectors complex up to the end of the HL-LHC era (ca. 2040). [...]
2024 - 8 p.
- Published in : JACoW HB 2023 (2024) 1-8
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.1-8
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Understanding of the LHC warm vacuum module heating
/ Krkotic, Patrick (CERN) ; Baglin, Vincent (CERN) ; Chiggiato, Paolo (CERN) ; Papaphilippou, Yannis (CERN) ; Rumolo, Giovanni (CERN) ; Antuono, Chiara (CERN ; Rome U.) ; Bregliozzi, Giuseppe (CERN) ; Calatroni, Sergio (CERN) ; de la Fuente, Elena (CERN ; Madrid, Polytechnic U.) ; Galloro, Alessio (Calabria U. ; CERN) et al.
During the third run of the Large Hadron Collider in 2023, which had the highest intensity bunch population compared to previous runs, increased losses attributed to pressure spikes within a warm vacuum sector triggered a beam dump. Subsequent inspections revealed localised annealing and plasticisation of the tension spring in the sliding contact radio-frequency finger module, alongside traces of vapour deposition on the various module components with the stainless-steel spring material. [...]
2024 - 4 p.
- Published in : JACoW IPAC 2024 (2024) TUAN3
Fulltext: PDF;
In : 15th International Particle Accelerator Conference (IPAC 2024), Nashville, TN, United States, 19 - 24 May 2024, pp.TUAN3
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6.
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CERN-SPS Wire Scanner Impedance and Wire Heating Studies
/ Berrig, OE ; Caspers, F ; Dehning, B ; Emery, J ; Hamani, M ; Kuczerowski, J ; Piselli, E ; Salvant, B ; Sautier, R ; Veness, R et al.
This article describes a study performed on one of the CERN-SPS vertical rotational wire scanners in order to investigate the breakage of the wire, which occurred on several occasions during operation in 2012. [...]
CERN-BE-2014-006.
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2014. - 5 p.
Full text
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7.
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A Wireless Method to Obtain the Impedance From Scattering Parameters
/ Antuono, Chiara (CERN) ; Migliorati, Mauro (Frascati) ; Mostacci, Andrea (Frascati) ; Métral, Elias (CERN) ; Zannini, Carlo (CERN)
The coaxial wire method is a common and appreciated choice to assess the beam coupling impedance of an accelerator element from scattering parameters. Nevertheless, the results obtained from wire measurements could be inaccurate due to the presence of the stretched conductive wire that artificially creates the conditions for the propagation of a Transverse ElectroMagnetic (TEM) mode. [...]
2022 - 4 p.
- Published in : JACoW IPAC 2022 (2022) 2213-2216
Fulltext: PDF;
In : 13th International Particle Accelerator Conference (IPAC 2022), Bangkok, Thailand, 12 - 17 Jun 2022, pp.2213-2216
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Studies and mitigation of TMCI in FCC-ee
/ Migliorati, Mauro (Rome U. ; INFN, Rome) ; Zannini, Carlo (CERN) ; Antuono, Chiara (CERN) ; Gibellieri, Dora (Rome U. ; CERN) ; Zobov, Mikhail (Frascati) ; Behtouei, Mostafa (Frascati) ; Soos, Roxana (IJCLab, Orsay ; CERN) ; Zhang, Yuan (Beijing, Inst. High Energy Phys.)
Previous studies have identified turbulent mode coupling instability (TMCI) as one of the most severe single-bunch instabilities in the FCC-ee collider, potentially limiting its performance. Its threshold is influenced by both transverse and longitudinal wakefields arising from vacuum chamber resistive wall effects, discontinuities, and beam-beam interactions, the latter of which can be seen as a transverse cross-wake force.In this paper, we investigate the TMCI using the most recent collider parameters and an updated impedance model. [...]
2024 - 4 p.
- Published in : JACoW IPAC 2024 (2024) THPC60
Fulltext: PDF;
In : 15th International Particle Accelerator Conference (IPAC 2024), Nashville, TN, United States, 19 - 24 May 2024, pp.THPC60
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A Wireless Method for Beam Coupling Impedance Measurements of the LHC Goniometer
/ Antuono, Chiara (CERN ; U. Rome La Sapienza (main)) ; Migliorati, Mauro (U. Rome La Sapienza (main)) ; Mostacci, Andrea (U. Rome La Sapienza (main)) ; Zannini, Carlo (CERN)
The beam coupling impedance (BCI) of an accelerator component should be ideally evaluated exciting the device with the beam itself. However, this scenario is not always attainable and alternative methods must be exploited, such as the bench measurements techniques. [...]
2024 - 4 p.
- Published in : JACoW HB 2023 (2024) 407-410
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.407-410
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A Novel Method for Transverse Beam-Coupling Impedance Measurements in Particle Accelerator Devices Using the Bead-Pull Method
/ Antuono, Chiara (U. Rome La Sapienza (main) ; CERN) ; Sito, Leonardo (CERN ; Naples U.) ; Calzone, Eleonora (U. Rome La Sapienza (main) ; CERN) ; el Dali, D (CERN) ; Migliorati, Mauro (CERN ; U. Rome La Sapienza (main)) ; Mostacci, Andrea (CERN ; U. Rome La Sapienza (main)) ; Fienga, Francesco (CERN ; Naples U.) ; Marrazzo, Vincenzo Romano (CERN ; Naples U.) ; Breglio, Giovanni (CERN ; Naples U.) ; Rumolo, G (CERN) et al.
In high-energy particle accelerators, circulating particle beams with high intensity interact electromagnetically with their surroundings (i.e., metallic vacuum chambers of various geometries). These electromagnetic interactions, which are typically described through the concept of beam-coupling impedance, can represent a serious issue in terms of stability of the particle beam and heating on the accelerator structures. [...]
2024 - 9 p.
- Published in : IEEE Trans. Instrum. Meas. 73 (2024) 8005209
Fulltext: PDF;
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