IPAC2022 - List of Authors (Calaga, R.)

Paper	Title	Page
TUPOTK015	HOM Coupler Design and Optimization for the FCC-ee W Working Point	1230
SUSPMF108	use link to see paper's listing under its alternate paper code
	S. Udongwo, S.G. Zadeh, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany R. Calaga CERN, Meyrin, Switzerland
	Funding: Funded by CERN under ADDENDUM FCC-GOV-CC-00213 (KE4978/ ATS) to FCC-GOV-CC- 0213/2431149/KE4978 VERSION 1.0. The Future Circular electron-positron Collider (FCC-ee) is planned to operate with beam energies from 45.6 to 182.5 GeV and beam currents from 5.4 to 1390 mA. The purpose is to study the properties of the Z-, W- and Higgs boson and the top and anti-top quarks in four operation points. The beam current of 147 mA of the W working point requires particular care to string damp HOMs. This paper proposes 2-cell 400 MHz SRF cavities with improved damping as an alternative to the baseline 4-cell cavities for this working point. The resulting impedance of the HOM-damped cavity is then calculated and compared with the impedance budget.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK015
About •	Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOTK064	HL-LHC Crab Cavity HOM Couplers: Challenges and Results	1374
	J.A. Mitchell, R. Calaga, E. Montesinos CERN, Meyrin, Switzerland
	To compensate for the detrimental effect of the crossing angle on luminosity production in the High Luminosity Large Hadron Collider’s (HL-LHC) interaction regions, superconducting crab cavities (vertical and horizontal) will be installed at the two interaction regions of the ATLAS and CMS experiments. Both cavity designs use multiple Higher Order Mode (HOM) couplers to reduce beam instabilities and heat loads caused by the very high proton current in the HL-LHC. The conceptual RF designs of the HOM couplers are firstly presented, evaluating HOM damping requirements, fundamental mode rejection and dynamic heat load constraints. A special focus is given to the coupler’s characteristic impedance (Z0), to improve the robustness during transport and operation. Following this, RF measurements of the HOM couplers before installation, installed on the superconducting cavities and with a circulating proton beam are detailed, analysing deviations from the simulated cases.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK064
About •	Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 10 July 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEOZSP2	Suppression of Crab Cavity Noise Induced Emittance Growth by Transverse Beam Coupling Impedance	1659
SUSPMF068	use link to see paper's listing under its alternate paper code
	N. Triantafyllou, A. Wolski The University of Liverpool, Liverpool, United Kingdom F. Antoniou, H. Bartosik, P. Baudrenghien, X. Buffat, R. Calaga, Y. Papaphilippou CERN, Meyrin, Switzerland T. Mastoridis CalPoly, San Luis Obispo, California, USA
	Crab Cavities are a key component of the High Luminosity LHC (HL-LHC) upgrade, as they aim to minimize the luminosity reduction caused by the crossing angle. Two superconducting crab cavities were installed in the Super Proton Synchrotron (SPS) at CERN in 2018 to test their operation in a proton machine for the first time. An important point to consider is the increase in transverse emittance induced by noise in the Low-Level RF (LLRF) system. During the first experimental campaign in 2018, the measured emittance growth was found to be a factor of 4 lower than predicted by the available analytical models. In this report, the effects of transverse beam impedance in the presence of CC LLRF noise on transverse emittance growth are presented and the results of the second experimental campaign, which took place in the SPS in 2021, are discussed.
	Slides WEOZSP2 [2.694 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEOZSP2
About •	Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 15 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOPT009	Operational Scenario of First High Luminosity LHC Run	1846
	R. Tomás García, G. Arduini, P. Baudrenghien, R. Bruce, O.S. Brüning, X. Buffat, R. Calaga, F. Cerutti, R. De Maria, J. Dilly, I. Efthymiopoulos, M. Giovannozzi, P.D. Hermes, G. Iadarola, O.R. Jones, S. Kostoglou, E.H. Maclean, N. Mounet, E. Métral, Y. Papaphilippou, S. Redaelli, G. Sterbini, H. Timko, F.F. Van der Veken, J. Wenninger, M. Zerlauth CERN, Meyrin, Switzerland
	A new scenario for the first operational run of the HL-LHC era (Run 4) has been recently developed to accommodate a period of performance ramp-up to achieve an annual integrated luminosity close to the nominal HL-LHC design. The operational scenario in terms of beam parameters and machine settings, as well as the different phases, are described here along with the impact of potential delays on key hardware components.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT009
About •	Received ※ 19 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 09 July 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

TUPOTK015

HOM Coupler Design and Optimization for the FCC-ee W Working Point

1230

SUSPMF108

use link to see paper's listing under its alternate paper code

S. Udongwo, S.G. Zadeh, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
R. Calaga
CERN, Meyrin, Switzerland

Funding: Funded by CERN under ADDENDUM FCC-GOV-CC-00213 (KE4978/ ATS) to FCC-GOV-CC- 0213/2431149/KE4978 VERSION 1.0.
The Future Circular electron-positron Collider (FCC-ee) is planned to operate with beam energies from 45.6 to 182.5 GeV and beam currents from 5.4 to 1390 mA. The purpose is to study the properties of the Z-, W- and Higgs boson and the top and anti-top quarks in four operation points. The beam current of 147 mA of the W working point requires particular care to string damp HOMs. This paper proposes 2-cell 400 MHz SRF cavities with improved damping as an alternative to the baseline 4-cell cavities for this working point. The resulting impedance of the HOM-damped cavity is then calculated and compared with the impedance budget.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK015

About •

Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022

Cite •

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

TUPOTK064

HL-LHC Crab Cavity HOM Couplers: Challenges and Results

1374

J.A. Mitchell, R. Calaga, E. Montesinos
CERN, Meyrin, Switzerland

To compensate for the detrimental effect of the crossing angle on luminosity production in the High Luminosity Large Hadron Collider’s (HL-LHC) interaction regions, superconducting crab cavities (vertical and horizontal) will be installed at the two interaction regions of the ATLAS and CMS experiments. Both cavity designs use multiple Higher Order Mode (HOM) couplers to reduce beam instabilities and heat loads caused by the very high proton current in the HL-LHC. The conceptual RF designs of the HOM couplers are firstly presented, evaluating HOM damping requirements, fundamental mode rejection and dynamic heat load constraints. A special focus is given to the coupler’s characteristic impedance (Z0), to improve the robustness during transport and operation. Following this, RF measurements of the HOM couplers before installation, installed on the superconducting cavities and with a circulating proton beam are detailed, analysing deviations from the simulated cases.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK064

About •

Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 10 July 2022

Cite •

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

WEOZSP2

Suppression of Crab Cavity Noise Induced Emittance Growth by Transverse Beam Coupling Impedance

1659

SUSPMF068

use link to see paper's listing under its alternate paper code

N. Triantafyllou, A. Wolski
The University of Liverpool, Liverpool, United Kingdom
F. Antoniou, H. Bartosik, P. Baudrenghien, X. Buffat, R. Calaga, Y. Papaphilippou
CERN, Meyrin, Switzerland
T. Mastoridis
CalPoly, San Luis Obispo, California, USA

Crab Cavities are a key component of the High Luminosity LHC (HL-LHC) upgrade, as they aim to minimize the luminosity reduction caused by the crossing angle. Two superconducting crab cavities were installed in the Super Proton Synchrotron (SPS) at CERN in 2018 to test their operation in a proton machine for the first time. An important point to consider is the increase in transverse emittance induced by noise in the Low-Level RF (LLRF) system. During the first experimental campaign in 2018, the measured emittance growth was found to be a factor of 4 lower than predicted by the available analytical models. In this report, the effects of transverse beam impedance in the presence of CC LLRF noise on transverse emittance growth are presented and the results of the second experimental campaign, which took place in the SPS in 2021, are discussed.

Slides WEOZSP2 [2.694 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEOZSP2

About •

Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 15 June 2022

Cite •

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

WEPOPT009

Operational Scenario of First High Luminosity LHC Run

1846

R. Tomás García, G. Arduini, P. Baudrenghien, R. Bruce, O.S. Brüning, X. Buffat, R. Calaga, F. Cerutti, R. De Maria, J. Dilly, I. Efthymiopoulos, M. Giovannozzi, P.D. Hermes, G. Iadarola, O.R. Jones, S. Kostoglou, E.H. Maclean, N. Mounet, E. Métral, Y. Papaphilippou, S. Redaelli, G. Sterbini, H. Timko, F.F. Van der Veken, J. Wenninger, M. Zerlauth
CERN, Meyrin, Switzerland

A new scenario for the first operational run of the HL-LHC era (Run 4) has been recently developed to accommodate a period of performance ramp-up to achieve an annual integrated luminosity close to the nominal HL-LHC design. The operational scenario in terms of beam parameters and machine settings, as well as the different phases, are described here along with the impact of potential delays on key hardware components.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT009

About •

Received ※ 19 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 09 July 2022

Cite •

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