IPAC2017 - List of Authors (Bruce, R.)

Paper	Title	Page
MOPAB001	Status of the FCC-hh Collimation System	64
	J. Molson, A. Faus-Golfe LAL, Orsay, France R. Bruce, M. Fiascaris, A.M. Krainer, S. Redaelli CERN, Geneva, Switzerland
	Funding: Funding from the European Union's Horizon 2020 research and innovation programme under grant No 654305. The future circular hadron collider (FCC-hh) will have an unprecedented proton beam energy of 50 TeV, and total stored beam energy of 8.4 GJ. We discuss current developments in the collimation system design, and methods with which the challenges faced due to the high energies involved can be mitigated. Finally simulation results of new collimation system designs are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB001
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB003	Energy Deposition in the Betatron Collimation Insertion of the 100 TeV Future Circular Collider	68
	M.I. Besana, C. Bahamonde Castro, A. Bertarelli, R. Bruce, F. Carra, F. Cerutti, A. Ferrari, M. Fiascaris, A. Lechner, A. Mereghetti, S. Redaelli, E. Skordis, V. Vlachoudis CERN, Geneva, Switzerland
	The FCC proton beam is designed to carry a total energy of about 8500 MJ, a factor of 20 above the LHC. In this context, the collimation system has to deal with extremely tight requirements to prevent quenches and material damage. A first layout of the betatron cleaning insertion was conceived, adapting the present LHC collimation system to the FCC lattice. A crucial ingredient to assess its performance, in particular to estimate the robustness of the protection devices and the load on the downstream elements, is represented by the simulation of the particle shower generated at the collimators, allowing detailed energy deposition estimations. This paper presents the first results of the simulation chain starting from the proton losses generated with the Sixtrack-FLUKA coupling, as currently done for the present LHC and for its upgrade. Expectations in terms of total power, peak power density and integrated dose on the different accelerator components are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB003
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB006	Design and Prototyping of New CERN Collimators in the Framework of the LHC Injector Upgrade (LIU) Project and the High-Luminosity (HL-LHC) Project	80
	F.-X. Nuiry, O. Aberle, M. Bergeret, A. Bertarelli, N. Biancacci, R. Bruce, M. Calviani, F. Carra, A. Dallocchio, L. Gentini, S.S. Gilardoni, R. Illan Fiastre, I. Lamas Garcia, A. Masi, A. Perillo-Marcone, S. Pianese, S. Redaelli, E. Rigutto, B. Salvant CERN, Geneva, Switzerland
	In the framework of the Large Hadron Collider (LHC) Injectors Upgrade (LIU) and the High-Luminosity LHC (HL-LHC) Projects at CERN (European Organization for Nuclear Research, in Geneva, Switzerland), collimators in the Super Proton Synchrotron (SPS) to LHC transfer lines as well as ring collimators in the LHC will undergo important upgrades in the forthcoming years, mainly focused during the Long Shutdown 2 foreseen during 2019-2020. This contribution will detail the current design of the TCDIL collimators with a particular emphasis on the engineering developments performed on the collimator jaws, aiming at getting a stringent flatness while consid-ering also the integration of thermal shock resistant materials. The prototyping phase done at CERN will be also described. The activities ongoing to prepare the series production for other LHC collimator types (TCPPM, TCSPM, TCTPM, TCLD) will be presented, describing the role that each of these collimators play on the HL-LHC Project. A focus on the series production processes, the manufacturing and assembly technologies involved and the quality and performance assurance tests will be given.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB006
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB010	Anomaly Detection for Beam Loss Maps in the Large Hadron Collider	92
	G. Valentino University of Malta, Information and Communication Technology, Msida, Malta R. Bruce, S. Redaelli, R. Rossi, P. Theodoropoulos CERN, Geneva, Switzerland S. Jaster-Merz University of Hamburg, Hamburg, Germany
	In the LHC, beam loss maps are used to validate collimator settings for cleaning and machine protection. This is done by monitoring the loss distribution in the ring during infrequent controlled loss map campaigns, as well as in standard operation. Due to the complexity of the system, consisting of more than 50 collimators per beam, it is difficult to identify small changes in the collimation hierarchy, which may be due to setting errors or beam orbit drifts with such methods. A technique based on Principal Component Analysis and Local Outlier Factor is presented to detect anomalies in the loss maps and therefore provide an automatic check of the collimation hierarchy.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB010
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB011	Impact on the HL-LHC Triplet Region and Experiments From Asynchronous Beam Dumps on Tertiary Collimators	96
	A. Tsinganis, R. Bruce, F. Cerutti, A. Lechner CERN, Geneva, Switzerland
	Accidental beam impacts on the tertiary collimators (TCTs) can lead to significant energy deposition in the triplet region and to leakage of the induced particle shower towards the experimental cavern. In this work, carried out in the context of the planned High Luminosity Upgrade of the LHC, severe impacts from asynchronous beam dumps on the horizontal tertiary collimators in cells 4 and 6 of the CMS insertion were studied, with half or a full proton bunch impacting on a collimator jaw. The choice of jaw material is shown to be of great importance, with over a factor of 10 increase in peak energy density values in the triplet coils moving from tungsten (Inermet) to molybdenum graphite jaws. Nevertheless, although the quench limit is exceeded in at least one or more triplet magnets in all the evaluated scenarios, values remain well below the damage limit. Energy spectra of particles leaking into the experimental cavern have also been estimated and are presented here.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB011
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB012	Study of the 2015 Top Energy LHC Collimation Quench Tests Through an Advanced Simulation Chain	100
SUSPSIK009	use link to see paper's listing under its alternate paper code
	E. Skordis, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom R. Bruce, F. Cerutti, A. Ferrari, P.D. Hermes, A. Lechner, A. Mereghetti, S. Redaelli, B. Salvachua, E. Skordis, V. Vlachoudis CERN, Geneva, Switzerland C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	While the LHC has shown record-breaking perfor-mance during the 2016 run, our understanding of the behaviour of the machine must also reach new levels. The collimation system and especially the betatron cleaning insertion region (IR7), where most of the beam halo is intercepted to protect superconducting (SC) magnets from quenching, has so far met the expectations but could nonetheless pose a bottleneck for future operation at higher beam intensities for HL-LHC. A better under-standing of the collimation leakage to SC magnets is required in order to quantify potential limitations in terms of cleaning efficiency, ultimately optimising the collider capabilities. Particle tracking simulations com-bined with shower simulations represent a powerful tool for quantifying the power deposition in magnets next to the cleaning insertion. In this study, we benchmark the simulation models against beam loss monitor measure-ments from magnet quench tests (QT) with 6.5 TeV pro-ton and 6.37Z TeV Pb ion beams. In addition, we investi-gate the effect of possible imperfections on the collima-tion leakage and the power deposition in magnets.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB012
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEOBA1	A Comparison of Interaction Physics for Proton Collimation Systems in Current Simulation Tools	2478
	J. Molson, A. Faus-Golfe LAL, Orsay, France R.B. Appleby, S.C. Tygier UMAN, Manchester, United Kingdom R.J. Barlow IIAA, Huddersfield, United Kingdom R. Bruce, F. Cerutti, A. Ferrari, A. Mereghetti, S. Redaelli, K.N. Sjobak, V. Vlachoudis CERN, Geneva, Switzerland H. Rafique University of Manchester, Manchester, United Kingdom Y. Zou IHEP, Beijing, People's Republic of China
	Funding: The European Circular Energy-Frontier Collider Study (EuroCirCol) project has received funding from the European Union's Horizon 2020 research and innovation programme under grant No 654305. High performance collimation systems are required for current and proposed high energy hadron accelerators in order to protect superconducting magnets and experiments. In order to ensure that the collimation system designs are sufficient and will operate as expected, precision simulation tools are required. This paper discusses the current status of existing collimation system tools, and performs a comparison between codes in order to ensure that the simulated interaction physics between a proton and a collimator jaw is accurate.
	Slides WEOBA1 [7.235 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEOBA1
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEOBA2	Hollow Electron Beam Collimation for HL-LHC - Effects on the Beam Core	2482
	M. Fitterer, G. Stancari, A. Valishev Fermilab, Batavia, Illinois, USA R. Bruce, G. Papotti, S. Redaelli, D. Valuch, C. Xu CERN, Geneva, Switzerland G. Valentino University of Malta, Information and Communication Technology, Msida, Malta
	Funding: Fermilab is operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the US Department of Energy. Collimation with hollow electron beams is currently one of the most promising concepts for active halo control in the High Luminosity Large Hadron Collider (HL-LHC). To ensure the successful operation of the hollow beam collimator the unwanted effects on the beam core, which might arise from the operation with a pulsed electron beam, must be minimized. This paper gives a summary of the effect of hollow electron lenses on the beam core in terms of sources, provides estimates for HL-LHC and discusses the possible mitigation methods.
	Slides WEOBA2 [2.074 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEOBA2
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPIK030	Experimental Validation of the Achromatic Telescopic Squeezing Scheme at the LHC	2992
	S.D. Fartoukh, R. Bruce, F.S. Carlier, J.M. Coello de Portugal, A. Garcia-Tabares, E.H. Maclean, L. Malina, A. Mereghetti, D. Mirarchi, T. Persson, M. Pojer, L. Ponce, S. Redaelli, B. Salvachua, P.K. Skowroński, M. Solfaroli, R. Tomás, D. Valuch, A. Wegscheider, J. Wenninger CERN, Geneva, Switzerland
	The Achromatic Telescopic Squeezing (ATS) [1] scheme offers new techniques to deliver unprecedentedly small beam spot size at the interaction points of the ATLAS and CMS experiments of the LHC, while perfectly controlling the chromatic properties of the corresponding optics (linear and non-linear chromaticities, off-momentum beta-beating, spurious dispersion induced by the crossing bumps). The first series of beam tests with ATS optics were achieved during the LHC Run I (2011/2012) for a first validation of the basics of the scheme at small intensity. In 2016, a new generation of more performing ATS optics was developed and more extensively tested in the machine, still with probe beams for optics measurement and correction at β^=10 cm, but also with a few nominal bunches to establish first collisions at nominal β^ (40 cm) and beyond (33 cm), and to analysis the robustness of these optics in terms of collimation and machine protection. The paper will highlight the most relevant and conclusive results which were obtained during this second series of ATS tests. [1] S. Fartoukh , Phys. Rev. ST Accel. Beams 16, 111002
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK030
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAB046	SixTrack for Cleaning Studies: 2017 Updates	3811
	A. Mereghetti, R. Bruce, F. Cerutti, R. De Maria, A. Ferrari, M. Fiascaris, P.D. Hermes, D. Mirarchi, P.G. Ortega, D. Pastor Sinuela, E. Quaranta, S. Redaelli, K.N. Sjobak, V. Vlachoudis CERN, Geneva, Switzerland J. Molson LAL, Orsay, France Y. Zou IHEP, Beijing, People's Republic of China
	SixTrack is a single particle tracking code for simulating beam dynamics in ultra-relativistic accelerators. It is widely used at the European Organisation for Nuclear Research (CERN) for predicting dynamic aperture and cleaning inefficiency in large circular machines like the Super Proton Synchrotron (SPS), the Large Hadron Collider (LHC) and the Future Circular Collider (FCC). The code is under continuous development, to both extend its physics models, and enhance performance. The present work gives an overview of developments, specifically aimed at extending the code capabilities for cleaning studies. They mainly involve: the online aperture check; the possibility to perform simulations coupled to advanced Monte Carlo codes like Fluka or using the scattering event generator of the Merlin code; the generalisation of tracking maps to ion species; the implementation of composite materials of relevance for the future upgrades of the LHC collimators; the physics of interactions with bent crystals. Plans to merge these functionalities into a single version of the SixTrack code will be outlined.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB046
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Status of the FCC-hh Collimation System

64

J. Molson, A. Faus-Golfe
LAL, Orsay, France
R. Bruce, M. Fiascaris, A.M. Krainer, S. Redaelli
CERN, Geneva, Switzerland

Funding: Funding from the European Union's Horizon 2020 research and innovation programme under grant No 654305.
The future circular hadron collider (FCC-hh) will have an unprecedented proton beam energy of 50 TeV, and total stored beam energy of 8.4 GJ. We discuss current developments in the collimation system design, and methods with which the challenges faced due to the high energies involved can be mitigated. Finally simulation results of new collimation system designs are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB001

Export •

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

MOPAB003

Energy Deposition in the Betatron Collimation Insertion of the 100 TeV Future Circular Collider

68

M.I. Besana, C. Bahamonde Castro, A. Bertarelli, R. Bruce, F. Carra, F. Cerutti, A. Ferrari, M. Fiascaris, A. Lechner, A. Mereghetti, S. Redaelli, E. Skordis, V. Vlachoudis
CERN, Geneva, Switzerland

The FCC proton beam is designed to carry a total energy of about 8500 MJ, a factor of 20 above the LHC. In this context, the collimation system has to deal with extremely tight requirements to prevent quenches and material damage. A first layout of the betatron cleaning insertion was conceived, adapting the present LHC collimation system to the FCC lattice. A crucial ingredient to assess its performance, in particular to estimate the robustness of the protection devices and the load on the downstream elements, is represented by the simulation of the particle shower generated at the collimators, allowing detailed energy deposition estimations. This paper presents the first results of the simulation chain starting from the proton losses generated with the Sixtrack-FLUKA coupling, as currently done for the present LHC and for its upgrade. Expectations in terms of total power, peak power density and integrated dose on the different accelerator components are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB003

Export •

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

MOPAB006

Design and Prototyping of New CERN Collimators in the Framework of the LHC Injector Upgrade (LIU) Project and the High-Luminosity (HL-LHC) Project

80

F.-X. Nuiry, O. Aberle, M. Bergeret, A. Bertarelli, N. Biancacci, R. Bruce, M. Calviani, F. Carra, A. Dallocchio, L. Gentini, S.S. Gilardoni, R. Illan Fiastre, I. Lamas Garcia, A. Masi, A. Perillo-Marcone, S. Pianese, S. Redaelli, E. Rigutto, B. Salvant
CERN, Geneva, Switzerland

In the framework of the Large Hadron Collider (LHC) Injectors Upgrade (LIU) and the High-Luminosity LHC (HL-LHC) Projects at CERN (European Organization for Nuclear Research, in Geneva, Switzerland), collimators in the Super Proton Synchrotron (SPS) to LHC transfer lines as well as ring collimators in the LHC will undergo important upgrades in the forthcoming years, mainly focused during the Long Shutdown 2 foreseen during 2019-2020. This contribution will detail the current design of the TCDIL collimators with a particular emphasis on the engineering developments performed on the collimator jaws, aiming at getting a stringent flatness while consid-ering also the integration of thermal shock resistant materials. The prototyping phase done at CERN will be also described. The activities ongoing to prepare the series production for other LHC collimator types (TCPPM, TCSPM, TCTPM, TCLD) will be presented, describing the role that each of these collimators play on the HL-LHC Project. A focus on the series production processes, the manufacturing and assembly technologies involved and the quality and performance assurance tests will be given.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB006

Export •

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

MOPAB010

Anomaly Detection for Beam Loss Maps in the Large Hadron Collider

92

G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta
R. Bruce, S. Redaelli, R. Rossi, P. Theodoropoulos
CERN, Geneva, Switzerland
S. Jaster-Merz
University of Hamburg, Hamburg, Germany

In the LHC, beam loss maps are used to validate collimator settings for cleaning and machine protection. This is done by monitoring the loss distribution in the ring during infrequent controlled loss map campaigns, as well as in standard operation. Due to the complexity of the system, consisting of more than 50 collimators per beam, it is difficult to identify small changes in the collimation hierarchy, which may be due to setting errors or beam orbit drifts with such methods. A technique based on Principal Component Analysis and Local Outlier Factor is presented to detect anomalies in the loss maps and therefore provide an automatic check of the collimation hierarchy.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB010

Export •

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

MOPAB011

Impact on the HL-LHC Triplet Region and Experiments From Asynchronous Beam Dumps on Tertiary Collimators

96

A. Tsinganis, R. Bruce, F. Cerutti, A. Lechner
CERN, Geneva, Switzerland

Accidental beam impacts on the tertiary collimators (TCTs) can lead to significant energy deposition in the triplet region and to leakage of the induced particle shower towards the experimental cavern. In this work, carried out in the context of the planned High Luminosity Upgrade of the LHC, severe impacts from asynchronous beam dumps on the horizontal tertiary collimators in cells 4 and 6 of the CMS insertion were studied, with half or a full proton bunch impacting on a collimator jaw. The choice of jaw material is shown to be of great importance, with over a factor of 10 increase in peak energy density values in the triplet coils moving from tungsten (Inermet) to molybdenum graphite jaws. Nevertheless, although the quench limit is exceeded in at least one or more triplet magnets in all the evaluated scenarios, values remain well below the damage limit. Energy spectra of particles leaking into the experimental cavern have also been estimated and are presented here.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB011

Export •

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

MOPAB012

Study of the 2015 Top Energy LHC Collimation Quench Tests Through an Advanced Simulation Chain

100

SUSPSIK009

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

E. Skordis, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
R. Bruce, F. Cerutti, A. Ferrari, P.D. Hermes, A. Lechner, A. Mereghetti, S. Redaelli, B. Salvachua, E. Skordis, V. Vlachoudis
CERN, Geneva, Switzerland
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

While the LHC has shown record-breaking perfor-mance during the 2016 run, our understanding of the behaviour of the machine must also reach new levels. The collimation system and especially the betatron cleaning insertion region (IR7), where most of the beam halo is intercepted to protect superconducting (SC) magnets from quenching, has so far met the expectations but could nonetheless pose a bottleneck for future operation at higher beam intensities for HL-LHC. A better under-standing of the collimation leakage to SC magnets is required in order to quantify potential limitations in terms of cleaning efficiency, ultimately optimising the collider capabilities. Particle tracking simulations com-bined with shower simulations represent a powerful tool for quantifying the power deposition in magnets next to the cleaning insertion. In this study, we benchmark the simulation models against beam loss monitor measure-ments from magnet quench tests (QT) with 6.5 TeV pro-ton and 6.37Z TeV Pb ion beams. In addition, we investi-gate the effect of possible imperfections on the collima-tion leakage and the power deposition in magnets.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB012

Export •

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

WEOBA1

A Comparison of Interaction Physics for Proton Collimation Systems in Current Simulation Tools

2478

J. Molson, A. Faus-Golfe
LAL, Orsay, France
R.B. Appleby, S.C. Tygier
UMAN, Manchester, United Kingdom
R.J. Barlow
IIAA, Huddersfield, United Kingdom
R. Bruce, F. Cerutti, A. Ferrari, A. Mereghetti, S. Redaelli, K.N. Sjobak, V. Vlachoudis
CERN, Geneva, Switzerland
H. Rafique
University of Manchester, Manchester, United Kingdom
Y. Zou
IHEP, Beijing, People's Republic of China

Funding: The European Circular Energy-Frontier Collider Study (EuroCirCol) project has received funding from the European Union's Horizon 2020 research and innovation programme under grant No 654305.
High performance collimation systems are required for current and proposed high energy hadron accelerators in order to protect superconducting magnets and experiments. In order to ensure that the collimation system designs are sufficient and will operate as expected, precision simulation tools are required. This paper discusses the current status of existing collimation system tools, and performs a comparison between codes in order to ensure that the simulated interaction physics between a proton and a collimator jaw is accurate.

Slides WEOBA1 [7.235 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEOBA1

Export •

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

WEOBA2

Hollow Electron Beam Collimation for HL-LHC - Effects on the Beam Core

2482

M. Fitterer, G. Stancari, A. Valishev
Fermilab, Batavia, Illinois, USA
R. Bruce, G. Papotti, S. Redaelli, D. Valuch, C. Xu
CERN, Geneva, Switzerland
G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta

Funding: Fermilab is operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the US Department of Energy.
Collimation with hollow electron beams is currently one of the most promising concepts for active halo control in the High Luminosity Large Hadron Collider (HL-LHC). To ensure the successful operation of the hollow beam collimator the unwanted effects on the beam core, which might arise from the operation with a pulsed electron beam, must be minimized. This paper gives a summary of the effect of hollow electron lenses on the beam core in terms of sources, provides estimates for HL-LHC and discusses the possible mitigation methods.

Slides WEOBA2 [2.074 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEOBA2

Export •

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

WEPIK030

Experimental Validation of the Achromatic Telescopic Squeezing Scheme at the LHC

2992

S.D. Fartoukh, R. Bruce, F.S. Carlier, J.M. Coello de Portugal, A. Garcia-Tabares, E.H. Maclean, L. Malina, A. Mereghetti, D. Mirarchi, T. Persson, M. Pojer, L. Ponce, S. Redaelli, B. Salvachua, P.K. Skowroński, M. Solfaroli, R. Tomás, D. Valuch, A. Wegscheider, J. Wenninger
CERN, Geneva, Switzerland

The Achromatic Telescopic Squeezing (ATS) [1] scheme offers new techniques to deliver unprecedentedly small beam spot size at the interaction points of the ATLAS and CMS experiments of the LHC, while perfectly controlling the chromatic properties of the corresponding optics (linear and non-linear chromaticities, off-momentum beta-beating, spurious dispersion induced by the crossing bumps). The first series of beam tests with ATS optics were achieved during the LHC Run I (2011/2012) for a first validation of the basics of the scheme at small intensity. In 2016, a new generation of more performing ATS optics was developed and more extensively tested in the machine, still with probe beams for optics measurement and correction at β^*=10 cm, but also with a few nominal bunches to establish first collisions at nominal β^* (40 cm) and beyond (33 cm), and to analysis the robustness of these optics in terms of collimation and machine protection. The paper will highlight the most relevant and conclusive results which were obtained during this second series of ATS tests.
[1] S. Fartoukh , Phys. Rev. ST Accel. Beams 16, 111002

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK030

Export •

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

THPAB046

SixTrack for Cleaning Studies: 2017 Updates

3811

A. Mereghetti, R. Bruce, F. Cerutti, R. De Maria, A. Ferrari, M. Fiascaris, P.D. Hermes, D. Mirarchi, P.G. Ortega, D. Pastor Sinuela, E. Quaranta, S. Redaelli, K.N. Sjobak, V. Vlachoudis
CERN, Geneva, Switzerland
J. Molson
LAL, Orsay, France
Y. Zou
IHEP, Beijing, People's Republic of China

SixTrack is a single particle tracking code for simulating beam dynamics in ultra-relativistic accelerators. It is widely used at the European Organisation for Nuclear Research (CERN) for predicting dynamic aperture and cleaning inefficiency in large circular machines like the Super Proton Synchrotron (SPS), the Large Hadron Collider (LHC) and the Future Circular Collider (FCC). The code is under continuous development, to both extend its physics models, and enhance performance. The present work gives an overview of developments, specifically aimed at extending the code capabilities for cleaning studies. They mainly involve: the online aperture check; the possibility to perform simulations coupled to advanced Monte Carlo codes like Fluka or using the scattering event generator of the Merlin code; the generalisation of tracking maps to ion species; the implementation of composite materials of relevance for the future upgrades of the LHC collimators; the physics of interactions with bent crystals. Plans to merge these functionalities into a single version of the SixTrack code will be outlined.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB046

Export •

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