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Correlating start-of-ramp losses with beam observables at blat-bottom in the LHC
/ Karlsen-Bæck, Birk Emil (CERN ; Rome U.) ; Salvachua, Belen (CERN) ; Timko, Helga (CERN) ; Zampetakis, Michail (CERN) ; Morales Vigo, Sara (CERN)
Power limitations are expected at injection energy for the main Radio Frequency (RF) system due to the doubled bunch intensity in the High Luminosity (HL-) Large Hadron Collider (LHC) era. One way to overcome these power limitations is to reduce the capture voltage. [...]
2024 - 4 p.
- Published in : JACoW IPAC 2024 (2024) MOPC11
Fulltext: PDF;
In : 15th International Particle Accelerator Conference (IPAC 2024), Nashville, TN, United States, 19 - 24 May 2024, pp.MOPC11
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2.
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Modelling intra-beam scattering in the LHC for longitudinal beam loss studies
/ Zampetakis, Michail (CERN) ; Karlsen-Bæck, Birk Emil (CERN ; Rome U.) ; Timko, Helga (CERN) ; Iliakis, Konstantinos (CERN)
In the Large Hadron Collider (LHC), intra-beam scattering (IBS) is one of the main drivers of longitudinal emittance growth during the long injection plateau. With the halo of the longitudinal bunch distribution being close to the separatrix, IBS consequently drives beam losses by pushing particles outside the RF bucket at the flat-bottom. [...]
2024 - 4 p.
- Published in : JACoW IPAC 2024 (2024) WEPR55
Fulltext: PDF;
In : 15th International Particle Accelerator Conference (IPAC 2024), Nashville, TN, United States, 19 - 24 May 2024, pp.WEPR55
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3.
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Effects of Cavity Pre-Detuning on RF Power Transients at Injection into the LHC
/ Karlsen-Bæck, Birk Emil (CERN ; Rome U.) ; Argyropoulos, Theodoros (CERN) ; Butterworth, Andrew (CERN) ; Calaga, Rama (CERN) ; Karpov, Ivan (CERN) ; Timko, Helga (CERN) ; Zampetakis, Michail (CERN)
At injection into the LHC, the RF system is perturbed by beam-induced voltage resulting in strong RF power transients and the instant detuning of the cavities. The automatic tuning system, however, needs time for the mechanical compensation of the resonance frequency to take place. [...]
2024 - 4 p.
- Published in : JACoW HB 2023 (2024) 530-533
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.530-533
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4.
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Refining the LHC Longitudinal Impedance Model
/ Zampetakis, Michail (CERN) ; Argyropoulos, Theodoros (CERN) ; Brischetto, Ylenia (CERN) ; Calaga, Rama (CERN) ; Giacomel, Lorenzo (CERN) ; Karlsen-Bæck, Birk Emil (INFN, Rome ; Rome U. ; CERN) ; Karpov, Ivan (CERN) ; Mounet, Nicolas (CERN) ; Salvant, Benoit (CERN) ; Timko, Helga (CERN)
Modelling the longitudinal impedance for the Large Hadron Collider (LHC) has been a long-standing effort, especially in view of its High-Luminosity (HL) upgrade. The resulting impedance model is an essential input for beam dynamics studies. [...]
2024 - 4 p.
- Published in : JACoW HB 2023 (2024) 559-562
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.559-562
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5.
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Advances on LHC RF Power Limitation Studies at Injection
/ Timko, Helga (CERN) ; Argyropoulos, Theodoros (CERN) ; Calaga, Rama (CERN) ; Catalán Lasheras, Nuria (CERN) ; Iliakis, Konstantinos (CERN) ; Karlsen-Bæck, Birk Emil (CERN ; Rome U.) ; Karpov, Ivan (CERN) ; Zampetakis, Michail (CERN)
The average power consumption of the main RF system during beam injection in the High-Luminosity Large Hadron Collider is expected to be close to the maximum available klystron power. Power transients due to the mismatch of the beam and the action of control loops will exceed the available power. [...]
2024 - 4 p.
- Published in : JACoW HB 2023 (2024) 567-570
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.567-570
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6.
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Machine learning-based extraction of longitudinal beam parameters in the LHC
/ Iliakis, Konstantinos (CERN) ; Karlsen-Bæck, Birk Emil (CERN) ; Trad, Georges (CERN) ; Timko, Helga (CERN) ; Zampetakis, Michail (CERN) ; Argyropoulos, Theodoros (CERN)
Accurate knowledge of beam parameters is essential for optimizing the performance of particle accelerators like the Large Hadron Collider (LHC). An initial machine-learning (ML) model for the reconstruction of the longitudinal distribution has been extended to extract the main parameters of multiple bunches at LHC injection. [...]
2024 - 4 p.
- Published in : JACoW IPAC 2024 (2024) TUPS56
Fulltext: PDF;
In : 15th International Particle Accelerator Conference (IPAC 2024), Nashville, TN, United States, 19 - 24 May 2024, pp.TUPS56
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7.
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Validation of control loop modeling for power limitation studies with beams for HL-LHC
/ Karlsen-Bæck, B E (CERN ; Rome U.) ; Argyropoulos, T (CERN) ; Calaga, R (CERN) ; Karpov, I (CERN) ; Timko, H (CERN)
For HL-LHC intensities, transient beam loading after injection between the Super Proton Synchrotron (SPS) and the Large Hadron Collider (LHC) is expected to push the RF power in the LHC to the limit of the installed system. A detailed understanding of this process is necessary to minimize beam losses during LHC injection. [...]
2023 - 4 p.
- Published in : JACoW IPAC 2023 (2023) TUPA160
Fulltext: PDF;
In : 14th International Particle Accelerator Conference (IPAC 2023), Venice, Italy, 7 - 12 May 2023, pp.TUPA160
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8.
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BLM thresholds and damage limits for collimators
/ Mereghetti, A (CERN) ; Bruce, R (CERN) ; Holzer, E B (CERN) ; Kalliokoski, M (CERN) ; Redaelli, S (CERN) ; Ferrando, B Salvachua (CERN)
LHC operation at 6.5 TeV required updating the collima-tor BLM thresholds
adopted in Run 1. At startup in 2015, the BLM thresholds at collimators were
computed by scaling linearly the values in 2012 to 6.5 TeV, following the
dependence on beam energy deployed during Run 1. [...]
Geneva : CERN, 2016 - 6 p.
- Published in : (2016) , pp. 197-202
Fulltext: PDF;
In : 6th Evian Workshop on LHC beam operation, Evian Les Bains, France, 15 - 17 Dec 2015, pp.197-202
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9.
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Detailed characterisation of the LEIR intensity limitations for a Pb ion beam
/ Saá Hernández, Angela (CERN) ; Bartosik, Hannes (CERN) ; Biancacci, Nicolo (CERN) ; Hirlaender, Simon (CERN) ; Moreno, Daniel (CERN) ; Zampetakis, Michail (CERN)
The equilibrium emittance of the Pb beam in the CERN Low Energy Ion Ring (LEIR) results from the interplay of electron cooling and heating processes, as intra-beam scattering and space charge. In this paper we present the measurements of the emittance evolution as a function of intensity, working point and resonance excitation, and compare them with the simulations of the heating processes. [...]
CERN-ACC-2019-109.-
2019 - 4 p.
- Published in : 10.18429/JACoW-IPAC2019-WEPTS042
Preprint: PDF;
In : 10th International Particle Accelerator Conference, Melbourne, Australia, 19 - 24 May 2019, pp.WEPTS042
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10.
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Effects of cavity pre-detuning on RF power transients at injection into the LHC
/ Karlsen-Baeck, B E (CERN ; Rome U.) ; Argyropoulos, T (CERN) ; Butterworth, A (CERN) ; Calaga, R (CERN) ; Karpov, I (CERN) ; Timko, H (CERN) ; Zampetakis, M (CERN)
At injection into the Large Hadron Collider (LHC), the radiofrequency (RF) system is perturbed by beam-induced voltage resultingin strong RF power transients and the instant detuning of thecavities. The automatic tuning system, however, needs time for themechanical compensation of the resonance frequency to takeplace. [...]
2024 - 8 p.
- Published in : JINST 19 (2024) T04005
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.T04005
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