IPAC2017 - List of Authors (Biancacci, N.)

Paper	Title	Page
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
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TUPVA020	The LHC Injectors Upgrade (LIU) Project at CERN: Ion Injector Chain	2089
	H. Bartosik, S.C.P. Albright, M.E. Angoletta, G. Bellodi, N. Biancacci, T. Bohl, J. Coupard, H. Damerau, A. Funken, B. Goddard, S. Hancock, K. Hanke, A. Huschauer, J.M. Jowett, V. Kain, D. Küchler, D. Manglunki, M. Meddahi, G. Rumolo, R. Scrivens, E.N. Shaposhnikova, V. Toivanen, F.J.C. Wenander CERN, Geneva, Switzerland
	The LHC injector chain for Pb-ion beams at CERN consists of Linac3, the accumulator ring LEIR, the PS and the SPS. In the context of the LHC injectors upgrade (LIU) project an intense program of machine development studies has been performed in the last two years to maximise the intensity of Pb-ion beams at LHC injection. In this paper we present an analysis of the operational performance achieved so far, with the goal of 1) identifying the remaining performance bottlenecks along the chain and possible areas for improvement, and 2) to optimize the Pb-ion beam production scheme for the High Luminosity (HL-) LHC era. A consistent set of beam parameters for the HL-LHC era has been established taking into account the already achieved improvements as well as foreseen upgrades still to be implemented, such as slip stacking in the SPS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA020
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WEPIK094	LEIR Impedance Model and Coherent Beam Instability Observations	3159
	N. Biancacci, H. Bartosik, A. Huschauer, E. Métral, T.L. Rijoff, B. Salvant, R. Scrivens CERN, Geneva, Switzerland M. Migliorati University of Rome La Sapienza, Rome, Italy
	The LEIR machine is the first synchrotron in the ion acceleration chain at CERN and it is responsible to deliver high intensity ion beams to the LHC. Following the recent progress in the understanding of the intensity limitations, detailed studies of the machine impedance started. In this work we describe the present LEIR impedance model, detailing the contribution to the total longitudinal and transverse impedance of several machine element. We then compare the machine tune shift versus intensity predictions against measurements at injection energy and summarize the coherent instability observations in absence of transverse damper feedback.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK094
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WEPVA108	Operational Feedback and Analysis of Current and Future Designs of the Injection Protection Absorbers in the Large Hadron Collider at CERN	3517
	D. Carbajo Perez, N. Biancacci, C. Bracco, G. Bregliozzi, M. Calviani, M.I. Frankl, L. Gentini, S.S. Gilardoni, G. Iadarola, I. Lamas Garcia, A. Lechner, A. Perillo-Marcone, B. Salvant CERN, Geneva, Switzerland
	Two injection protection absorbers, so-called TDIs (Target Dump Injection), are installed close to Interaction Points IP2 and IP8 of the Large Hadron Collider (LHC) right downstream of the injection kicker magnets (MKI). Malfunction or timing errors in the latter lead to wrong steering of the beam, which must then be intercepted by the TDI to avoid downstream equipment (which includes superconducting magnets) damage. In recent years, MKI failures during operation have brought to light opportunities for improvement of the TDI. The upgrade of this absorber, so-called TDIS (where S stands for segmented), is conceived as part of the High Luminosity-LHC (HL-LHC) project and those operational issues are taken into account for its design. The present document describes not only the aspects related to the current TDI performance and their impact in its successor's design but also the key modifications to cope with the stronger requirements associated to the higher luminosity goal.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA108
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THPAB005	Improvement of the Analytic Vlasov Solver DELPHI	3688
	D. Amorim Université Grenoble Alpes, Grenoble, France N. Biancacci, K.S.B. Li, E. Métral CERN, Geneva, Switzerland
	The simulation code DELPHI is an analytic Vlasov solver which allows to evaluate the beam transverse stability with respect to impedance effects. It allows to perform fast scans over parameters such as chromaticity, damper gain or beam intensity for a given impedance model and particle distribution. In order to improve the simulation code, new longitudinal particle distributions have been implemented. The simulations results obtained with these distributions are compared to theoretical predictions. An additional post-processing of DELPHI's output has also been implemented, allowing to reconstruct the signal seen by head-tail stripline monitors, in particular in presence of bunch-by-bunch damper. The results are compared to theoretical models, to pyHEADTAIL simulations and to measurements performed in the LHC.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB005
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THPAB040	Destabilising Effect of Linear Coupling in the LHC	3791
	L.R. Carver, D. Amorim, N. Biancacci, X. Buffat, K.S.B. Li, E. Métral, B. Salvant, M. Schenk CERN, Geneva, Switzerland
	During operation in 2015 and 2016, some transverse instabilities were observed when either the coupling (or closest tune approach) C- was large, or when the tunes were moved closer together. This motivated a campaign of simulations on the effect of linear coupling on the transverse stability. Measurements made during operation and with dedicated beam time have been found to confirm the predictions. This paper will detail the results of the linear coupling studies and relate them to operation of the LHC in the future.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB040
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THPVA026	Practical Stabilisation of Transverse Collective Instabilities with Second Order Chromaticity in the LHC	4477
SUSPSIK059	use link to see paper's listing under its alternate paper code
	M. Schenk, D. Amorim, N. Biancacci, X. Buffat, L.R. Carver, R. De Maria, K.S.B. Li, E. Métral, B. Salvant CERN, Geneva, Switzerland
	The study reports on dedicated measurements made with a single nominal bunch in the LHC at 6.5 TeV. First, we show that a significant amount of second order chromaticity Q'' can be introduced in the machine in a well-controlled manner. Second, we demonstrate that the incoherent betatron tune spread from Q'' can provide beam stability through the Landau damping mechanism. This is a first step in the development of a Q'' knob to be potentially applied during regular physics operation in the LHC.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPVA026
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Paper

Title

Page

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)

TUPVA020

The LHC Injectors Upgrade (LIU) Project at CERN: Ion Injector Chain

2089

H. Bartosik, S.C.P. Albright, M.E. Angoletta, G. Bellodi, N. Biancacci, T. Bohl, J. Coupard, H. Damerau, A. Funken, B. Goddard, S. Hancock, K. Hanke, A. Huschauer, J.M. Jowett, V. Kain, D. Küchler, D. Manglunki, M. Meddahi, G. Rumolo, R. Scrivens, E.N. Shaposhnikova, V. Toivanen, F.J.C. Wenander
CERN, Geneva, Switzerland

The LHC injector chain for Pb-ion beams at CERN consists of Linac3, the accumulator ring LEIR, the PS and the SPS. In the context of the LHC injectors upgrade (LIU) project an intense program of machine development studies has been performed in the last two years to maximise the intensity of Pb-ion beams at LHC injection. In this paper we present an analysis of the operational performance achieved so far, with the goal of 1) identifying the remaining performance bottlenecks along the chain and possible areas for improvement, and 2) to optimize the Pb-ion beam production scheme for the High Luminosity (HL-) LHC era. A consistent set of beam parameters for the HL-LHC era has been established taking into account the already achieved improvements as well as foreseen upgrades still to be implemented, such as slip stacking in the SPS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA020

Export •

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WEPIK094

LEIR Impedance Model and Coherent Beam Instability Observations

3159

N. Biancacci, H. Bartosik, A. Huschauer, E. Métral, T.L. Rijoff, B. Salvant, R. Scrivens
CERN, Geneva, Switzerland
M. Migliorati
University of Rome La Sapienza, Rome, Italy

The LEIR machine is the first synchrotron in the ion acceleration chain at CERN and it is responsible to deliver high intensity ion beams to the LHC. Following the recent progress in the understanding of the intensity limitations, detailed studies of the machine impedance started. In this work we describe the present LEIR impedance model, detailing the contribution to the total longitudinal and transverse impedance of several machine element. We then compare the machine tune shift versus intensity predictions against measurements at injection energy and summarize the coherent instability observations in absence of transverse damper feedback.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK094

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

WEPVA108

Operational Feedback and Analysis of Current and Future Designs of the Injection Protection Absorbers in the Large Hadron Collider at CERN

3517

D. Carbajo Perez, N. Biancacci, C. Bracco, G. Bregliozzi, M. Calviani, M.I. Frankl, L. Gentini, S.S. Gilardoni, G. Iadarola, I. Lamas Garcia, A. Lechner, A. Perillo-Marcone, B. Salvant
CERN, Geneva, Switzerland

Two injection protection absorbers, so-called TDIs (Target Dump Injection), are installed close to Interaction Points IP2 and IP8 of the Large Hadron Collider (LHC) right downstream of the injection kicker magnets (MKI). Malfunction or timing errors in the latter lead to wrong steering of the beam, which must then be intercepted by the TDI to avoid downstream equipment (which includes superconducting magnets) damage. In recent years, MKI failures during operation have brought to light opportunities for improvement of the TDI. The upgrade of this absorber, so-called TDIS (where S stands for segmented), is conceived as part of the High Luminosity-LHC (HL-LHC) project and those operational issues are taken into account for its design. The present document describes not only the aspects related to the current TDI performance and their impact in its successor's design but also the key modifications to cope with the stronger requirements associated to the higher luminosity goal.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA108

Export •

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

THPAB005

Improvement of the Analytic Vlasov Solver DELPHI

3688

D. Amorim
Université Grenoble Alpes, Grenoble, France
N. Biancacci, K.S.B. Li, E. Métral
CERN, Geneva, Switzerland

The simulation code DELPHI is an analytic Vlasov solver which allows to evaluate the beam transverse stability with respect to impedance effects. It allows to perform fast scans over parameters such as chromaticity, damper gain or beam intensity for a given impedance model and particle distribution. In order to improve the simulation code, new longitudinal particle distributions have been implemented. The simulations results obtained with these distributions are compared to theoretical predictions. An additional post-processing of DELPHI's output has also been implemented, allowing to reconstruct the signal seen by head-tail stripline monitors, in particular in presence of bunch-by-bunch damper. The results are compared to theoretical models, to pyHEADTAIL simulations and to measurements performed in the LHC.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB005

Export •

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

THPAB040

Destabilising Effect of Linear Coupling in the LHC

3791

L.R. Carver, D. Amorim, N. Biancacci, X. Buffat, K.S.B. Li, E. Métral, B. Salvant, M. Schenk
CERN, Geneva, Switzerland

During operation in 2015 and 2016, some transverse instabilities were observed when either the coupling (or closest tune approach) C- was large, or when the tunes were moved closer together. This motivated a campaign of simulations on the effect of linear coupling on the transverse stability. Measurements made during operation and with dedicated beam time have been found to confirm the predictions. This paper will detail the results of the linear coupling studies and relate them to operation of the LHC in the future.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB040

Export •

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

THPVA026

Practical Stabilisation of Transverse Collective Instabilities with Second Order Chromaticity in the LHC

4477

SUSPSIK059

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

M. Schenk, D. Amorim, N. Biancacci, X. Buffat, L.R. Carver, R. De Maria, K.S.B. Li, E. Métral, B. Salvant
CERN, Geneva, Switzerland

The study reports on dedicated measurements made with a single nominal bunch in the LHC at 6.5 TeV. First, we show that a significant amount of second order chromaticity Q'' can be introduced in the machine in a well-controlled manner. Second, we demonstrate that the incoherent betatron tune spread from Q'' can provide beam stability through the Landau damping mechanism. This is a first step in the development of a Q'' knob to be potentially applied during regular physics operation in the LHC.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPVA026

Export •

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