HB2023 - List of Authors (Mounet, N.)

Paper	Title	Page
TUA2C2	Recent Advances in the CERN PS Impedance Model and Instability Simulations	86
	S. Joly La Sapienza University of Rome, Rome, Italy G. Iadarola, N. Mounet, B. Salvant, C. Zannini CERN, Meyrin, Switzerland M. Migliorati INFN-Roma1, Rome, Italy
	Transverse instability growth rates in the CERN Proton Synchrotron are studied thanks to the recently updated impedance model of the machine. Using this model, macroparticle tracking simulations were performed with a new method well-suited for the slicing of short wakes, which achieves comparable performance to the originally implemented method while reducing the required number of slices by a factor of 5 to 10. Dedicated beam-based measurement campaigns were carried out to benchmark the impedance model. Until now, the model underestimated instability growth rates at injection energy. Thanks to a recent addition to the impedance model, namely the kicker magnets¿ connecting cables and their external circuits, the simulated instability growth rates are now comparable to the measured ones.
	Slides TUA2C2 [0.736 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-TUA2C2
About •	Received ※ 28 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 21 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUC4C2	Mitigating Collimation Impedance and Improving Halo Cleaning with New Optics and Settings Strategy of the HL-LHC Betatron Collimation System	183
	B. Lindström, R. Bruce, X. Buffat, R. De Maria, L. Giacomel, P.D. Hermes, D. Mirarchi, N. Mounet, T.H.B. Persson, S. Redaelli, R. Tomás García, F.F. Van der Veken, A. Wegscheider CERN, Meyrin, Switzerland
	Funding: Work supported by the HL-LHC project With High Luminosity Large Hadron Collider (HL-LHC) beam intensities, there are concerns that the beam losses in the dispersion suppressors around the betatron cleaning insertion might exceed the quench limits. Furthermore, to maximize the beam lifetime it is important to reduce the impedance as much as possible. The collimators constitute one of the main sources of impedance in HL-LHC, given the need to operate with small collimator gaps. To improve this, a new optics was developed which increases the beta function in the collimation area, as well as the single pass dispersion from the primary collimators to the downstream shower absorbers. Other possible improvements from orbit bumps, to further enhance the locally generated dispersion, and from asymmetric collimator settings were also studied. The new solutions were partially tested with 6.8 TeV beams at the LHC in a dedicated machine experiment in 2022. In this paper, the new performance is reviewed and prospects for future operational deployment are discussed.
	Slides TUC4C2 [2.222 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC4C2
About •	Received ※ 01 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 28 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THA1C1	High Intensity Beam Dynamics Challenges for HL-LHC	344
	N. Mounet, H. Bartosik, P. Baudrenghien, R. Bruce, X. Buffat, R. Calaga, R. De Maria, C.N. Droin, L. Giacomel, M. Giovannozzi, G. Iadarola, S. Kostoglou, B. Lindström, L. Mether, E. Métral, Y. Papaphilippou, K. Paraschou, S. Redaelli, G. Rumolo, B. Salvant, G. Sterbini, R. Tomás García CERN, Meyrin, Switzerland
	The High Luminosity (HL-LHC) project aims to increase the integrated luminosity of CERN’s Large Hadron Collider (LHC) by an order of magnitude compared to its initial design. This requires a large increase in bunch intensity and beam brightness compared to the first LHC runs, and hence poses serious collective-effects challenges, related in particular to electron cloud, instabilities from beam-coupling impedance, and beam-beam effects. Here we present the associated constraints and the proposed mitigation measures to achieve the baseline performance of the upgraded LHC machine. We also discuss the interplay of these mitigation measures with other aspects of the accelerator, such as the physical and dynamic aperture, machine protection, magnet imperfections, optics, and the collimation system.
	Slides THA1C1 [3.385 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THA1C1
About •	Received ※ 01 October 2023 — Revised ※ 10 October 2023 — Accepted ※ 12 October 2023 — Issued ※ 15 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THC2I2	Extraction of LHC Beam Parameters from Schottky Signals	382
	K. Łasocha, D. Alves, C. Lannoy, N. Mounet CERN, Meyrin, Switzerland C. Lannoy, T. Pieloni EPFL, Lausanne, Switzerland
	Analysis of Schottky signals provides rich insights into the dynamics of a hadron beam, with well-established methods of deriving the betatron tune and machine chromaticity. In this contribution, we will report on recent developments in the analysis and understanding of the signals measured at the Large Hadron Collider during proton and Pb⁸²⁺ fills. A fitting-based technique, where the measured spectra are iteratively compared with theoretical predictions, will be presented and compared with the previous methods. As a step beyond the classical theory of Schottky spectra, certain signal modifications due to the activity of the LHC machine systems will be discussed from the perspective of the applicability of the modified signal to the beam diagnostics.
	Slides THC2I2 [9.053 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THC2I2
About •	Received ※ 04 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 12 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP12	Slow vs Fast Landau Damping Threshold Measurement at the LHC and Implications for the HL-LHC	470
	X. Buffat, L. Giacomel, N. Mounet CERN, Meyrin, Switzerland
	The mechanism of Loss of Landau Damping by Diffusion (L2D2) was observed in dedicated experiments at the LHC using a controlled external source of noise. Nevertheless, the predictions of stability threshold by L2D2 models are plagued by the poor knowledge of the natural noise floor affecting the LHC beams. Experimental measurements of the stability threshold on slow and fast time scales are used to better constrain the model. The improved model is then used to quantify requirements in terms of Landau damping for the HL-LHC.
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP12
About •	Received ※ 29 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 30 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP37	Refining the LHC Longitudinal Impedance Model	559
	M. Zampetakis, T. Argyropoulos, Y. Brischetto, R. Calaga, L. Giacomel, B.E. Karlsen-Bæck, I. Karpov, I. Karpov, N. Mounet, B. Salvant, H. Timko CERN, Meyrin, Switzerland B.E. Karlsen-Bæck INFN-Roma, Roma, Italy
	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. Increased beam intensities in the HL-LHC era will pose new challenges like RF power limitations, beam losses at injection and coupled-bunch instabilities throughout the acceleration cycle. Starting from the existing longitudinal impedance model, effort has been made to identify the main contributing devices and improve their modelling. Loss of Landau damping (LLD) simulations are performed to investigate the dependence of the stability threshold on the completeness of the impedance model and its broad-band cut-off frequency. Plans to perform beam measurements to estimate the cut-off frequency, by investigating the LLD threshold in operation, are also discussed.
	Poster THBP37 [5.606 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP37
About •	Received ※ 01 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 14 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP40	Mitigation Strategies for the Instabilities Induced by the Fundamental Mode of the HL-LHC Crab Cavities	571
	L. Giacomel, P. Baudrenghien, X. Buffat, R. Calaga, N. Mounet CERN, Meyrin, Switzerland
	The transverse impedance is one of the potentially limiting effects for the performance of the High-Luminosity Large Hadron Collider (HL-LHC). In the current LHC, the impedance is dominated by the resistive-wall contribution of the collimators at typical bunch-spectrum frequencies, and is of broad-band nature. Nevertheless, the fundamental mode of the crab cavities, that are a vital part of the HL-LHC baseline, adds a strong and narrow-band contribution. The resulting coupled-bunch instability, which contains a strong head-tail component, requires dedicated mitigation measures, since the efficiency of the transverse damper is limited against such instabilities, and Landau damping from octupoles would not be sufficient. The efficiency and implications of various mitigation strategies, based on RF feedbacks and optics changes, are discussed, along with first measurements using crab cavity prototypes at the Super Proton Synchrotron (SPS).
	Poster THBP40 [0.461 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP40
About •	Received ※ 30 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 19 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP47	Studies on the Effect of Beam-Coupling Impedance on Schottky Spectra of Bunched Beams	595
	C. Lannoy, D. Alves, K. Łasocha, N. Mounet CERN, Meyrin, Switzerland C. Lannoy, T. Pieloni EPFL, Lausanne, Switzerland
	Schottky monitors can be used for non-invasive beam diagnostics to estimate various bunch characteristics, such as tune, chromaticity, bunch profile or synchrotron frequency distribution. However, collective effects, in particular beam-coupling impedance, can significantly affect Schottky spectra when large bunch charges are involved. In such conditions, the available interpretation methods are difficult to apply directly to the measured spectra, thus preventing the extraction of beam and machine parameters, which is possible for lower bunch charges. To study the impact of impedance on such spectra, we perform here time-domain, macro-particle simulations and apply a semi-analytical method to compute the Schottky signal for various machine and beam conditions, including those corresponding to typical physics operation at the Large Hadron Collider. This study provides preliminary interpretations of the impact of beam-coupling impedance on Schottky spectra by incorporating longitudinal and transverse resonator-like impedance models into the simulations.
	Poster THBP47 [1.133 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP47
About •	Received ※ 01 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 21 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP49	Collimation of 400 MJ Beams at the LHC: The First Step Towards the HL-LHC Era	603
	S. Redaelli, A. Abramov, D.B. Baillard, R. Bruce, R. Cai, F. Carra, M. D’Andrea, M. Di Castro, L. Giacomel, P.D. Hermes, B. Lindström, D. Mirarchi, N. Mounet, F.-X. Nuiry, A. Perillo Marcone, F.F. Van der Veken CERN, Meyrin, Switzerland R. Cai EPFL, Lausanne, Switzerland A. Vella University of Malta, Information and Communication Technology, Msida, Malta
	Funding: Work supported by the HL-LHC project. An important upgrade programme is planned for the collimation system of the CERN Large Hadron Collider (LHC) in order to meet the challenges of the upcoming High-Luminosity LHC (HL-LHC) project. A first stage of the HL-LHC upgrade was already deployed during the last LHC Long Shutdown, offering important improvements of the collimation cleaning, a significant reduction of the impedance contribution and better cleaning of collisional debris, in particular for ion-ion collisions. This upgrade provides a critical opportunity to explore the LHC intensity limits during the LHC Run 3 and can provide crucial feedback to refine upgrade plans and operational scenarios in the HL-LHC era. This paper describes the performance of the upgraded LHC collimation system that has already enabled stored-beam energies larger than 400 MJ at the unprecedented beam energy of 6.8 TeV, and reviews further upgrade plans envisaged to reach 700 MJ beams at the HL-LHC.
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP49
About •	Received ※ 03 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 10 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Recent Advances in the CERN PS Impedance Model and Instability Simulations

86

S. Joly
La Sapienza University of Rome, Rome, Italy
G. Iadarola, N. Mounet, B. Salvant, C. Zannini
CERN, Meyrin, Switzerland
M. Migliorati
INFN-Roma1, Rome, Italy

Transverse instability growth rates in the CERN Proton Synchrotron are studied thanks to the recently updated impedance model of the machine. Using this model, macroparticle tracking simulations were performed with a new method well-suited for the slicing of short wakes, which achieves comparable performance to the originally implemented method while reducing the required number of slices by a factor of 5 to 10. Dedicated beam-based measurement campaigns were carried out to benchmark the impedance model. Until now, the model underestimated instability growth rates at injection energy. Thanks to a recent addition to the impedance model, namely the kicker magnets¿ connecting cables and their external circuits, the simulated instability growth rates are now comparable to the measured ones.

Slides TUA2C2 [0.736 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-TUA2C2

About •

Received ※ 28 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 21 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUC4C2

Mitigating Collimation Impedance and Improving Halo Cleaning with New Optics and Settings Strategy of the HL-LHC Betatron Collimation System

183

B. Lindström, R. Bruce, X. Buffat, R. De Maria, L. Giacomel, P.D. Hermes, D. Mirarchi, N. Mounet, T.H.B. Persson, S. Redaelli, R. Tomás García, F.F. Van der Veken, A. Wegscheider
CERN, Meyrin, Switzerland

Funding: Work supported by the HL-LHC project
With High Luminosity Large Hadron Collider (HL-LHC) beam intensities, there are concerns that the beam losses in the dispersion suppressors around the betatron cleaning insertion might exceed the quench limits. Furthermore, to maximize the beam lifetime it is important to reduce the impedance as much as possible. The collimators constitute one of the main sources of impedance in HL-LHC, given the need to operate with small collimator gaps. To improve this, a new optics was developed which increases the beta function in the collimation area, as well as the single pass dispersion from the primary collimators to the downstream shower absorbers. Other possible improvements from orbit bumps, to further enhance the locally generated dispersion, and from asymmetric collimator settings were also studied. The new solutions were partially tested with 6.8 TeV beams at the LHC in a dedicated machine experiment in 2022. In this paper, the new performance is reviewed and prospects for future operational deployment are discussed.

Slides TUC4C2 [2.222 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC4C2

About •

Received ※ 01 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 28 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THA1C1

High Intensity Beam Dynamics Challenges for HL-LHC

344

N. Mounet, H. Bartosik, P. Baudrenghien, R. Bruce, X. Buffat, R. Calaga, R. De Maria, C.N. Droin, L. Giacomel, M. Giovannozzi, G. Iadarola, S. Kostoglou, B. Lindström, L. Mether, E. Métral, Y. Papaphilippou, K. Paraschou, S. Redaelli, G. Rumolo, B. Salvant, G. Sterbini, R. Tomás García
CERN, Meyrin, Switzerland

The High Luminosity (HL-LHC) project aims to increase the integrated luminosity of CERN’s Large Hadron Collider (LHC) by an order of magnitude compared to its initial design. This requires a large increase in bunch intensity and beam brightness compared to the first LHC runs, and hence poses serious collective-effects challenges, related in particular to electron cloud, instabilities from beam-coupling impedance, and beam-beam effects. Here we present the associated constraints and the proposed mitigation measures to achieve the baseline performance of the upgraded LHC machine. We also discuss the interplay of these mitigation measures with other aspects of the accelerator, such as the physical and dynamic aperture, machine protection, magnet imperfections, optics, and the collimation system.

Slides THA1C1 [3.385 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THA1C1

About •

Received ※ 01 October 2023 — Revised ※ 10 October 2023 — Accepted ※ 12 October 2023 — Issued ※ 15 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THC2I2

Extraction of LHC Beam Parameters from Schottky Signals

382

K. Łasocha, D. Alves, C. Lannoy, N. Mounet
CERN, Meyrin, Switzerland
C. Lannoy, T. Pieloni
EPFL, Lausanne, Switzerland

Analysis of Schottky signals provides rich insights into the dynamics of a hadron beam, with well-established methods of deriving the betatron tune and machine chromaticity. In this contribution, we will report on recent developments in the analysis and understanding of the signals measured at the Large Hadron Collider during proton and Pb⁸²⁺ fills. A fitting-based technique, where the measured spectra are iteratively compared with theoretical predictions, will be presented and compared with the previous methods. As a step beyond the classical theory of Schottky spectra, certain signal modifications due to the activity of the LHC machine systems will be discussed from the perspective of the applicability of the modified signal to the beam diagnostics.

Slides THC2I2 [9.053 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THC2I2

About •

Received ※ 04 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 12 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP12

Slow vs Fast Landau Damping Threshold Measurement at the LHC and Implications for the HL-LHC

470

X. Buffat, L. Giacomel, N. Mounet
CERN, Meyrin, Switzerland

The mechanism of Loss of Landau Damping by Diffusion (L2D2) was observed in dedicated experiments at the LHC using a controlled external source of noise. Nevertheless, the predictions of stability threshold by L2D2 models are plagued by the poor knowledge of the natural noise floor affecting the LHC beams. Experimental measurements of the stability threshold on slow and fast time scales are used to better constrain the model. The improved model is then used to quantify requirements in terms of Landau damping for the HL-LHC.

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP12

About •

Received ※ 29 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 30 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP37

Refining the LHC Longitudinal Impedance Model

559

M. Zampetakis, T. Argyropoulos, Y. Brischetto, R. Calaga, L. Giacomel, B.E. Karlsen-Bæck, I. Karpov, I. Karpov, N. Mounet, B. Salvant, H. Timko
CERN, Meyrin, Switzerland
B.E. Karlsen-Bæck
INFN-Roma, Roma, Italy

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. Increased beam intensities in the HL-LHC era will pose new challenges like RF power limitations, beam losses at injection and coupled-bunch instabilities throughout the acceleration cycle. Starting from the existing longitudinal impedance model, effort has been made to identify the main contributing devices and improve their modelling. Loss of Landau damping (LLD) simulations are performed to investigate the dependence of the stability threshold on the completeness of the impedance model and its broad-band cut-off frequency. Plans to perform beam measurements to estimate the cut-off frequency, by investigating the LLD threshold in operation, are also discussed.

Poster THBP37 [5.606 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP37

About •

Received ※ 01 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 14 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP40

Mitigation Strategies for the Instabilities Induced by the Fundamental Mode of the HL-LHC Crab Cavities

571

L. Giacomel, P. Baudrenghien, X. Buffat, R. Calaga, N. Mounet
CERN, Meyrin, Switzerland

The transverse impedance is one of the potentially limiting effects for the performance of the High-Luminosity Large Hadron Collider (HL-LHC). In the current LHC, the impedance is dominated by the resistive-wall contribution of the collimators at typical bunch-spectrum frequencies, and is of broad-band nature. Nevertheless, the fundamental mode of the crab cavities, that are a vital part of the HL-LHC baseline, adds a strong and narrow-band contribution. The resulting coupled-bunch instability, which contains a strong head-tail component, requires dedicated mitigation measures, since the efficiency of the transverse damper is limited against such instabilities, and Landau damping from octupoles would not be sufficient. The efficiency and implications of various mitigation strategies, based on RF feedbacks and optics changes, are discussed, along with first measurements using crab cavity prototypes at the Super Proton Synchrotron (SPS).

Poster THBP40 [0.461 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP40

About •

Received ※ 30 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 19 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP47

Studies on the Effect of Beam-Coupling Impedance on Schottky Spectra of Bunched Beams

595

C. Lannoy, D. Alves, K. Łasocha, N. Mounet
CERN, Meyrin, Switzerland
C. Lannoy, T. Pieloni
EPFL, Lausanne, Switzerland

Schottky monitors can be used for non-invasive beam diagnostics to estimate various bunch characteristics, such as tune, chromaticity, bunch profile or synchrotron frequency distribution. However, collective effects, in particular beam-coupling impedance, can significantly affect Schottky spectra when large bunch charges are involved. In such conditions, the available interpretation methods are difficult to apply directly to the measured spectra, thus preventing the extraction of beam and machine parameters, which is possible for lower bunch charges. To study the impact of impedance on such spectra, we perform here time-domain, macro-particle simulations and apply a semi-analytical method to compute the Schottky signal for various machine and beam conditions, including those corresponding to typical physics operation at the Large Hadron Collider. This study provides preliminary interpretations of the impact of beam-coupling impedance on Schottky spectra by incorporating longitudinal and transverse resonator-like impedance models into the simulations.

Poster THBP47 [1.133 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP47

About •

Received ※ 01 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 21 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP49

Collimation of 400 MJ Beams at the LHC: The First Step Towards the HL-LHC Era

603

S. Redaelli, A. Abramov, D.B. Baillard, R. Bruce, R. Cai, F. Carra, M. D’Andrea, M. Di Castro, L. Giacomel, P.D. Hermes, B. Lindström, D. Mirarchi, N. Mounet, F.-X. Nuiry, A. Perillo Marcone, F.F. Van der Veken
CERN, Meyrin, Switzerland
R. Cai
EPFL, Lausanne, Switzerland
A. Vella
University of Malta, Information and Communication Technology, Msida, Malta

Funding: Work supported by the HL-LHC project.
An important upgrade programme is planned for the collimation system of the CERN Large Hadron Collider (LHC) in order to meet the challenges of the upcoming High-Luminosity LHC (HL-LHC) project. A first stage of the HL-LHC upgrade was already deployed during the last LHC Long Shutdown, offering important improvements of the collimation cleaning, a significant reduction of the impedance contribution and better cleaning of collisional debris, in particular for ion-ion collisions. This upgrade provides a critical opportunity to explore the LHC intensity limits during the LHC Run 3 and can provide crucial feedback to refine upgrade plans and operational scenarios in the HL-LHC era. This paper describes the performance of the upgraded LHC collimation system that has already enabled stored-beam energies larger than 400 MJ at the unprecedented beam energy of 6.8 TeV, and reviews further upgrade plans envisaged to reach 700 MJ beams at the HL-LHC.

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP49

About •

Received ※ 03 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 10 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)