HB2023 - List of Authors (Métral, E.)

Paper	Title	Page
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)

THBP17	Transverse Coherent Instability Studies for the High-Energy Part of the Muon Collider Complex	491
	D. Amorim, F. Batsch, L. Bottura, D. Calzolari, C. Carli, H. Damerau, A. Grudiev, A. Lechner, E. Métral, D. Schulte, K. Skoufaris CERN, Meyrin, Switzerland A. Chancé CEA-DRF-IRFU, France T. Pieloni EPFL, Lausanne, Switzerland
	Funding: This project has received funding from the European Union¿s Research and Innovation programme under GA No 101094300 and the Swiss Accelerator Research and Technology (CHART) program (www.chart.ch). The International Muon Collider Collaboration (IMCC) is studying a 3 TeV center-of-mass muon collider ring, as well as a possible next stage at 10 TeV. Muons being 200 times heavier than electrons, limitations from synchrotron radiation are mostly suppressed, but the muon decay drives the accelerator chain design. After the muon and anti-muon bunches are produced and 6D cooled, a series of Linac, recirculating Linac and Rapid Cycling Synchrotron (RCS) quickly accelerate the bunches before the collider ring. A large number of RF cavities are required in the RCS to ensure that over 90% of the muons survive in each ring. The effects of cavities higher-order modes on transverse coherent stability have been looked at in detail, including the one of a bunch offset in the cavities, along with possible mitigation measures. In the collider ring, the decay of high-energy muons is a challenge for heat load management and radiation shielding. A tungsten liner would protect the superconducting magnet from decay products. Impedance and related beam stability have been investigated to identify the minimum vacuum chamber radius and transverse damper properties required for stable beams.
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP17
About •	Received ※ 29 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 01 November 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP43	Intensity Effects in a Chain of Muon RCSs	579
	F. Batsch, D. Amorim, H. Damerau, A. Grudiev, I. Karpov, E. Métral, D. Schulte CERN, Meyrin, Switzerland A. Chancé CEA, Gif-sur-Yvette, France S. Udongwo Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
	Funding: Funded by the European Union under Grant Agreement n.101094300 The muon collider offers an attractive path to a compact, multi-TeV lepton collider. However, the short muon lifetime leads to stringent requirements on the fast energy increase. While extreme energy gains in the order of several GeV per turn are crucial for a high elevated muon survival rate, ultra-short and intense bunches are needed to achieve large luminosity. The longitudinal beam dynamics of a chain of rapid cycling synchrotrons (RCS) for acceleration from around 60 GeV to several TeV is being investigated in the framework of the International Muon Collider Collaboration. Each RCS must have a distributed radio-frequency (RF) system with several hundred RF stations to establish stable synchrotron motion. In this contribution, the beam-induced voltage in each RCS is studied, assuming a single high-intensity bunch per beam in each direction and ILC-like 1.3 GHz accelerating structures. The impact of single- and multi-turn wakefields on longitudinal stability and RF power requirements is analysed with particle tracking simulations. Special attention is moreover paid to the beam power deposited into the higher-order modes of the RF cavities.
	Poster THBP43 [1.345 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP43
About •	Received ※ 29 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 10 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

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)

THBP17

Transverse Coherent Instability Studies for the High-Energy Part of the Muon Collider Complex

491

D. Amorim, F. Batsch, L. Bottura, D. Calzolari, C. Carli, H. Damerau, A. Grudiev, A. Lechner, E. Métral, D. Schulte, K. Skoufaris
CERN, Meyrin, Switzerland
A. Chancé
CEA-DRF-IRFU, France
T. Pieloni
EPFL, Lausanne, Switzerland

Funding: This project has received funding from the European Union¿s Research and Innovation programme under GA No 101094300 and the Swiss Accelerator Research and Technology (CHART) program (www.chart.ch).
The International Muon Collider Collaboration (IMCC) is studying a 3 TeV center-of-mass muon collider ring, as well as a possible next stage at 10 TeV. Muons being 200 times heavier than electrons, limitations from synchrotron radiation are mostly suppressed, but the muon decay drives the accelerator chain design. After the muon and anti-muon bunches are produced and 6D cooled, a series of Linac, recirculating Linac and Rapid Cycling Synchrotron (RCS) quickly accelerate the bunches before the collider ring. A large number of RF cavities are required in the RCS to ensure that over 90% of the muons survive in each ring. The effects of cavities higher-order modes on transverse coherent stability have been looked at in detail, including the one of a bunch offset in the cavities, along with possible mitigation measures. In the collider ring, the decay of high-energy muons is a challenge for heat load management and radiation shielding. A tungsten liner would protect the superconducting magnet from decay products. Impedance and related beam stability have been investigated to identify the minimum vacuum chamber radius and transverse damper properties required for stable beams.

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP17

About •

Received ※ 29 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 01 November 2023

Cite •

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

THBP43

Intensity Effects in a Chain of Muon RCSs

579

F. Batsch, D. Amorim, H. Damerau, A. Grudiev, I. Karpov, E. Métral, D. Schulte
CERN, Meyrin, Switzerland
A. Chancé
CEA, Gif-sur-Yvette, France
S. Udongwo
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany

Funding: Funded by the European Union under Grant Agreement n.101094300
The muon collider offers an attractive path to a compact, multi-TeV lepton collider. However, the short muon lifetime leads to stringent requirements on the fast energy increase. While extreme energy gains in the order of several GeV per turn are crucial for a high elevated muon survival rate, ultra-short and intense bunches are needed to achieve large luminosity. The longitudinal beam dynamics of a chain of rapid cycling synchrotrons (RCS) for acceleration from around 60 GeV to several TeV is being investigated in the framework of the International Muon Collider Collaboration. Each RCS must have a distributed radio-frequency (RF) system with several hundred RF stations to establish stable synchrotron motion. In this contribution, the beam-induced voltage in each RCS is studied, assuming a single high-intensity bunch per beam in each direction and ILC-like 1.3 GHz accelerating structures. The impact of single- and multi-turn wakefields on longitudinal stability and RF power requirements is analysed with particle tracking simulations. Special attention is moreover paid to the beam power deposited into the higher-order modes of the RF cavities.

Poster THBP43 [1.345 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP43

About •

Received ※ 29 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 10 October 2023

Cite •

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