IPAC2017 - List of Authors (Barranco, J.)

Paper	Title	Page
TUPVA031	Impact of Incoherent Effects on the Landau Stability Diagram at the LHC	2125
	C. Tambasco, J. Barranco García, X. Buffat, T. Pieloni CERN, Geneva, Switzerland J. Barranco García, X. Buffat, T. Pieloni EPFL, Lausanne, Switzerland
	Instability thresholds are explored at the Large Hadron Collider (LHC) by means of the computation of the Landau Stability Diagrams (SD). In the presence of diffusive mechanisms, caused by resonance excitations or noise, the SD can be reduced due to the modification of the particle distribution inside the beam. This effect can lead to a possible lack of Landau damping of the coherent modes previously damped by lying within the unperturbed SD area. The limitations deriving from coherent instabilities in the LHC is crucial in view of future projects that aim to increase the performance of the LHC such as the High-Luminosity upgrade (HL-LHC). Simulation tools for the computation of the SD have been extended in order to take into account the incoherent effects from long tracking through the detailed model of the accelerator machine. The model includes among others beam-beam interactions and octupoles and the interplay between both is addressed. Finally the simulation results are compared to the Beam Transfer Function (BTF) measurements in the LHC.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA031
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEOAB2	Correction of Beta-Beating Due to Beam-Beam for the LHC and Its Impact on Dynamic Aperture	2512
	L.E. Medina Medrano, J. Barranco García, X. Buffat, Y. Papaphilippou, T. Pieloni, R. Tomás CERN, Geneva, Switzerland J. Barranco García, T. Pieloni EPFL, Lausanne, Switzerland L.E. Medina Medrano UGTO, Leon, Mexico
	Funding: This work is supported by the European Circular Energy-Frontier Collider Study, H2020 programme under grant agreement no. 654305, by the Swiss State Secretariat for Education, Research and Innovation SERI, and by the Beam project (CONACYT, Mexico). Minimization of the beta-beating at the two main interaction points of the LHC arising from the head-on and long-range beam-beam interactions can be performed by adjusting the strength of quadrupole or sextupole correctors. This compensation scheme is applied to the current LHC optics where the results show a significant reduction of the peak and RMS beta-beating; and the impact on the dynamic aperture is computed. A proposal for a similar strategy to be adopted in the High Luminosity LHC is also discussed.
	Slides WEOAB2 [6.292 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEOAB2
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAB047	New Features of the 2017 SixTrack Release	3815
	K.N. Sjobak, J. Barranco García, R. De Maria, E. McIntosh, A. Mereghetti CERN, Geneva, Switzerland M. Fitterer Fermilab, Batavia, Illinois, USA V. Gupta IIT, Guwahati, Assam, India J. Molson LAL, Orsay, France
	The SixTrack particle tracking code is routinely used to simulate particle trajectories in high energy circular machines like the LHC and FCC, and is deployed for massive simulation campaigns on CERN clusters and on the BOINC platform within the LHC@Home volunteering computing project. The 2017 release brings many upgrades that improve flexibility, performance, and accuracy. This paper describes the new modules for wire- and electron lenses (WIRE and ELEN), the expert interface for beam-beam element (BEAM/EXPERT), the extension of the number of simultaneously tracked particles, the new Frequency Map Analysis (FMA) postprocessing option, the generation of a single zip of selected output files (ZIPF) in order to extend the coverage of the studies in LHC@HOME (e.g. FMA and on-line aperture checks), coupling to external codes (DYNK-PIPE and BDEX), a new CMAKE based build- and test mechanism, and internal restructuring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB047
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPVA025	Observations of Beam Losses at the LHC During Reduction of Crossing Angle	2105
	B. Salvachua, X. Buffat, A.A. Gorzawski, T. Pieloni, S. Redaelli, C. Tambasco, J. Wenninger CERN, Geneva, Switzerland J. Barranco García, A.A. Gorzawski EPFL, Lausanne, Switzerland M.P. Crouch UMAN, Manchester, United Kingdom
	Several machine development studies have been performed in 2016 at the LHC in order to evaluate the effects of reducing the crossing angles in favor of defining the maximum achievable luminosity in the ATLAS and CMS experiments. At the end of the LHC proton-proton run at 6.5TeV the reduction of the crossing angle from 185urad to 140urad was operationally implemented. The observation of beam losses and lifetimes during this process are analysed and discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA025
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPVA026	Beam-Beam Studies for FCC-hh	2109
	J. Barranco García, T. Pieloni, C. Tambasco EPFL, Lausanne, Switzerland X. Buffat, S.V. Furuseth, C. Tambasco CERN, Geneva, Switzerland S.V. Furuseth NTNU, Trondheim, Norway
	Funding: This works was performed in the framework of the European Circular 'Energy Fr'ontier Collider Study, H2020 Framework Programme under grant agreement no. 654305. We acknowledge support from the Swiss State Secretariat for Education, Research and Innovation SERI. The Future Circular Collider hadron-hadron (FCC-hh) design study is currently exploring different IR design possibilities including round and flat optics or different crossing schemes. The present study intends to evaluate each scenario from the beam-beam effects point of view. In particular the single particle long term stability to maximize beam lifetimes and luminosity reach is used to quantify the differences. The impact of strong head on interactions on the beam quality and lifetime is addressed by means of GPU accelerated simulations code featuring a weak-strong 6-dimensional beam-beam interaction.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA026
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPVA027	Study of Beam-Beam Long Range Compensation with Octupoles	2113
	T. Pieloni, J. Barranco García, C. Tambasco EPFL, Lausanne, Switzerland X. Buffat, C. Tambasco CERN, Geneva, Switzerland
	Funding: The European Circular Energy-Frontier Collider Study (EuroCirCol), EU's Horizon 2020 grant No 654305. Long range beam-beam effects are responsible for particle losses and define fundamental operational parameters of colliders (i.e. crossing angles, intensities, emittances, β^*). In this study we propose octuple magnets as a possible scheme to efficiently compensate long-range beam-beam interactions with a global correction scheme. The impact and improvements on the dynamic aperture of colliding beams together with estimates of the luminosity potentials are discussed for the HL-LHC upgrade and extrapolations made for the FCC project. Results are compared to other compensating schemes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA027
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPVA029	Observations of Emittance Growth in the Presence of External Noise in the LHC	2117
	X. Buffat, C. Tambasco, D. Valuch CERN, Geneva, Switzerland J. Barranco García, T. Pieloni, C. Tambasco EPFL, Lausanne, Switzerland
	Dedicated experiments were perfomed in the LHC to study the impact of noise on colliding high brightness beams. The results are compared to theoretical models and multiparticle tracking simulations. The impacts on the LHC operation and the HL-LHC project are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA029
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPVA030	Measurement of Beta-Beating Due to Strong Head-on Beam-Beam Interactions in the LHC	2121
	P. Gonçalves Jorge, J. Barranco García, T. Pieloni EPFL, Lausanne, Switzerland X. Buffat, F.S. Carlier, J.M. Coello de Portugal, E. Fol, L.E. Medina Medrano, R. Tomás, A. Wegscheider CERN, Geneva, Switzerland
	The LHC operation relies on a good knowledge of the optics, usually corrected in absence of beam-beam interactions. In a near future, both the LHC and the HL-LHC will need to cope with large head-on beam-beam parameters, the impact on the optics needs to be understood and, if necessary, corrected. The results of a dedicated experiment performed at injection energy are discussed in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA030
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPVA040	Overview of Design Development of FCC-hh Experimental Interaction Regions	2151
	A. Seryi, J.L. Abelleira, E. Cruz Alaniz, L.J. Nevay, L. van Riesen-Haupt JAI, Oxford, United Kingdom R.B. Appleby, H. Rafique UMAN, Manchester, United Kingdom R.B. Appleby Cockcroft Institute, Warrington, Cheshire, United Kingdom J. Barranco García, T. Pieloni EPFL, Lausanne, Switzerland M. Benedikt, M.I. Besana, X. Buffat, H. Burkhardt, F. Cerutti, A. Langner, R. Martin, W. Riegler, D. Schulte, R. Tomás CERN, Geneva, Switzerland M. Boscolo, F. Collamati INFN/LNF, Frascati (Roma), Italy M. Hofer TU Vienna, Wien, Austria L.J. Nevay Royal Holloway, University of London, Surrey, United Kingdom L. van Riesen-Haupt University of Oxford, Oxford, United Kingdom
	The experimental interaction region is one of the key areas that define the performance of the Future Circular Collider. In this overview we will describe the status and the evolution of the design of EIR of FCC-hh, focusing on design of the optics, energy deposition in EIR elements, beam-beam effects and machine detector interface issues.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA040
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAB056	Dynamic Aperture Studies of the Long-Range Beam-Beam Interaction at the LHC	3840
	M.P. Crouch, R.B. Appleby UMAN, Manchester, United Kingdom J. Barranco García, T. Pieloni, C. Tambasco EPFL, Lausanne, Switzerland X. Buffat, M. Giovannozzi, E.H. Maclean CERN, Geneva, Switzerland B.D. Muratori STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Long-range beam-beam interactions dictate the choice of operational parameters for the LHC, such as the crossing angle and β^* and therefore the luminosity reach for the collider. These effects can lead to particle losses, closed orbit effects and emittance growth. Defining how these effects depend on the beam-beam separation will determine the minimum crossing angle and the β^* the LHC can operate. In this article, analysis from a dedicated machine study is presented in which the crossing angle was reduced in steps and the impact on beam intensity and luminosity lifetimes were observed. Based on the observations during the machine study, the intensity decays are compared to expectations from models. Estimates of the luminosity reach in the LHC are also computed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB056
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Impact of Incoherent Effects on the Landau Stability Diagram at the LHC

2125

C. Tambasco, J. Barranco García, X. Buffat, T. Pieloni
CERN, Geneva, Switzerland
J. Barranco García, X. Buffat, T. Pieloni
EPFL, Lausanne, Switzerland

Instability thresholds are explored at the Large Hadron Collider (LHC) by means of the computation of the Landau Stability Diagrams (SD). In the presence of diffusive mechanisms, caused by resonance excitations or noise, the SD can be reduced due to the modification of the particle distribution inside the beam. This effect can lead to a possible lack of Landau damping of the coherent modes previously damped by lying within the unperturbed SD area. The limitations deriving from coherent instabilities in the LHC is crucial in view of future projects that aim to increase the performance of the LHC such as the High-Luminosity upgrade (HL-LHC). Simulation tools for the computation of the SD have been extended in order to take into account the incoherent effects from long tracking through the detailed model of the accelerator machine. The model includes among others beam-beam interactions and octupoles and the interplay between both is addressed. Finally the simulation results are compared to the Beam Transfer Function (BTF) measurements in the LHC.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA031

Export •

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

WEOAB2

Correction of Beta-Beating Due to Beam-Beam for the LHC and Its Impact on Dynamic Aperture

2512

L.E. Medina Medrano, J. Barranco García, X. Buffat, Y. Papaphilippou, T. Pieloni, R. Tomás
CERN, Geneva, Switzerland
J. Barranco García, T. Pieloni
EPFL, Lausanne, Switzerland
L.E. Medina Medrano
UGTO, Leon, Mexico

Funding: This work is supported by the European Circular Energy-Frontier Collider Study, H2020 programme under grant agreement no. 654305, by the Swiss State Secretariat for Education, Research and Innovation SERI, and by the Beam project (CONACYT, Mexico).
Minimization of the beta-beating at the two main interaction points of the LHC arising from the head-on and long-range beam-beam interactions can be performed by adjusting the strength of quadrupole or sextupole correctors. This compensation scheme is applied to the current LHC optics where the results show a significant reduction of the peak and RMS beta-beating; and the impact on the dynamic aperture is computed. A proposal for a similar strategy to be adopted in the High Luminosity LHC is also discussed.

Slides WEOAB2 [6.292 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEOAB2

Export •

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

THPAB047

New Features of the 2017 SixTrack Release

3815

K.N. Sjobak, J. Barranco García, R. De Maria, E. McIntosh, A. Mereghetti
CERN, Geneva, Switzerland
M. Fitterer
Fermilab, Batavia, Illinois, USA
V. Gupta
IIT, Guwahati, Assam, India
J. Molson
LAL, Orsay, France

The SixTrack particle tracking code is routinely used to simulate particle trajectories in high energy circular machines like the LHC and FCC, and is deployed for massive simulation campaigns on CERN clusters and on the BOINC platform within the LHC@Home volunteering computing project. The 2017 release brings many upgrades that improve flexibility, performance, and accuracy. This paper describes the new modules for wire- and electron lenses (WIRE and ELEN), the expert interface for beam-beam element (BEAM/EXPERT), the extension of the number of simultaneously tracked particles, the new Frequency Map Analysis (FMA) postprocessing option, the generation of a single zip of selected output files (ZIPF) in order to extend the coverage of the studies in LHC@HOME (e.g. FMA and on-line aperture checks), coupling to external codes (DYNK-PIPE and BDEX), a new CMAKE based build- and test mechanism, and internal restructuring.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB047

Export •

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

TUPVA025

Observations of Beam Losses at the LHC During Reduction of Crossing Angle

2105

B. Salvachua, X. Buffat, A.A. Gorzawski, T. Pieloni, S. Redaelli, C. Tambasco, J. Wenninger
CERN, Geneva, Switzerland
J. Barranco García, A.A. Gorzawski
EPFL, Lausanne, Switzerland
M.P. Crouch
UMAN, Manchester, United Kingdom

Several machine development studies have been performed in 2016 at the LHC in order to evaluate the effects of reducing the crossing angles in favor of defining the maximum achievable luminosity in the ATLAS and CMS experiments. At the end of the LHC proton-proton run at 6.5TeV the reduction of the crossing angle from 185urad to 140urad was operationally implemented. The observation of beam losses and lifetimes during this process are analysed and discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA025

Export •

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

TUPVA026

Beam-Beam Studies for FCC-hh

2109

J. Barranco García, T. Pieloni, C. Tambasco
EPFL, Lausanne, Switzerland
X. Buffat, S.V. Furuseth, C. Tambasco
CERN, Geneva, Switzerland
S.V. Furuseth
NTNU, Trondheim, Norway

Funding: This works was performed in the framework of the European Circular 'Energy Fr'ontier Collider Study, H2020 Framework Programme under grant agreement no. 654305. We acknowledge support from the Swiss State Secretariat for Education, Research and Innovation SERI.
The Future Circular Collider hadron-hadron (FCC-hh) design study is currently exploring different IR design possibilities including round and flat optics or different crossing schemes. The present study intends to evaluate each scenario from the beam-beam effects point of view. In particular the single particle long term stability to maximize beam lifetimes and luminosity reach is used to quantify the differences. The impact of strong head on interactions on the beam quality and lifetime is addressed by means of GPU accelerated simulations code featuring a weak-strong 6-dimensional beam-beam interaction.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA026

Export •

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

TUPVA027

Study of Beam-Beam Long Range Compensation with Octupoles

2113

T. Pieloni, J. Barranco García, C. Tambasco
EPFL, Lausanne, Switzerland
X. Buffat, C. Tambasco
CERN, Geneva, Switzerland

Funding: The European Circular Energy-Frontier Collider Study (EuroCirCol), EU's Horizon 2020 grant No 654305.
Long range beam-beam effects are responsible for particle losses and define fundamental operational parameters of colliders (i.e. crossing angles, intensities, emittances, β^*). In this study we propose octuple magnets as a possible scheme to efficiently compensate long-range beam-beam interactions with a global correction scheme. The impact and improvements on the dynamic aperture of colliding beams together with estimates of the luminosity potentials are discussed for the HL-LHC upgrade and extrapolations made for the FCC project. Results are compared to other compensating schemes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA027

Export •

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

TUPVA029

Observations of Emittance Growth in the Presence of External Noise in the LHC

2117

X. Buffat, C. Tambasco, D. Valuch
CERN, Geneva, Switzerland
J. Barranco García, T. Pieloni, C. Tambasco
EPFL, Lausanne, Switzerland

Dedicated experiments were perfomed in the LHC to study the impact of noise on colliding high brightness beams. The results are compared to theoretical models and multiparticle tracking simulations. The impacts on the LHC operation and the HL-LHC project are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA029

Export •

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

TUPVA030

Measurement of Beta-Beating Due to Strong Head-on Beam-Beam Interactions in the LHC

2121

P. Gonçalves Jorge, J. Barranco García, T. Pieloni
EPFL, Lausanne, Switzerland
X. Buffat, F.S. Carlier, J.M. Coello de Portugal, E. Fol, L.E. Medina Medrano, R. Tomás, A. Wegscheider
CERN, Geneva, Switzerland

The LHC operation relies on a good knowledge of the optics, usually corrected in absence of beam-beam interactions. In a near future, both the LHC and the HL-LHC will need to cope with large head-on beam-beam parameters, the impact on the optics needs to be understood and, if necessary, corrected. The results of a dedicated experiment performed at injection energy are discussed in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA030

Export •

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

TUPVA040

Overview of Design Development of FCC-hh Experimental Interaction Regions

2151

A. Seryi, J.L. Abelleira, E. Cruz Alaniz, L.J. Nevay, L. van Riesen-Haupt
JAI, Oxford, United Kingdom
R.B. Appleby, H. Rafique
UMAN, Manchester, United Kingdom
R.B. Appleby
Cockcroft Institute, Warrington, Cheshire, United Kingdom
J. Barranco García, T. Pieloni
EPFL, Lausanne, Switzerland
M. Benedikt, M.I. Besana, X. Buffat, H. Burkhardt, F. Cerutti, A. Langner, R. Martin, W. Riegler, D. Schulte, R. Tomás
CERN, Geneva, Switzerland
M. Boscolo, F. Collamati
INFN/LNF, Frascati (Roma), Italy
M. Hofer
TU Vienna, Wien, Austria
L.J. Nevay
Royal Holloway, University of London, Surrey, United Kingdom
L. van Riesen-Haupt
University of Oxford, Oxford, United Kingdom

The experimental interaction region is one of the key areas that define the performance of the Future Circular Collider. In this overview we will describe the status and the evolution of the design of EIR of FCC-hh, focusing on design of the optics, energy deposition in EIR elements, beam-beam effects and machine detector interface issues.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA040

Export •

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

THPAB056

Dynamic Aperture Studies of the Long-Range Beam-Beam Interaction at the LHC

3840

M.P. Crouch, R.B. Appleby
UMAN, Manchester, United Kingdom
J. Barranco García, T. Pieloni, C. Tambasco
EPFL, Lausanne, Switzerland
X. Buffat, M. Giovannozzi, E.H. Maclean
CERN, Geneva, Switzerland
B.D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Long-range beam-beam interactions dictate the choice of operational parameters for the LHC, such as the crossing angle and β^* and therefore the luminosity reach for the collider. These effects can lead to particle losses, closed orbit effects and emittance growth. Defining how these effects depend on the beam-beam separation will determine the minimum crossing angle and the β^* the LHC can operate. In this article, analysis from a dedicated machine study is presented in which the crossing angle was reduced in steps and the impact on beam intensity and luminosity lifetimes were observed. Based on the observations during the machine study, the intensity decays are compared to expectations from models. Estimates of the luminosity reach in the LHC are also computed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB056

Export •

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