IPAC2014 - List of Authors (Kain, V.)

Paper	Title	Page
MOPRO031	Abort Gap Cleaning for LHC Run 2	138
	J.A. Uythoven, A. Boccardi, E. Bravin, B. Goddard, G.H. Hemelsoet, W. Höfle, D. Jacquet, V. Kain, S. Mazzoni, M. Meddahi, D. Valuch CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA
	To minimize the beam losses at the moment of an LHC beam dump the 3 μs long abort gap should contain as few particles as possible. Its population can be minimised by abort gap cleaning using the LHC transverse damper system. The LHC Run 1 experience is briefly recalled; changes foreseen for the LHC Run 2 are presented. They include improvements in the observation of the abort gap population and the mechanism to decide if cleaning is required, changes to the hardware of the transverse dampers to reduce the detrimental effect on the luminosity lifetime and proposed changes to the applied cleaning algorithms.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO031
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRI096	The New Transfer Line Collimation System for the LHC High Luminosity Era	839
	V. Kain, C. Bracco, B. Goddard, F.L. Maciariello, M. Meddahi, A. Mereghetti, G.E. Steele, F.M. Velotti CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA
	A set of passive absorbers is located at the end of each of the 3 km long injection lines to protect the LHC in case of failures during the extraction process from the LHC’s last pre-injector or the beam transfer itself. In case of an erroneous extraction, the absorbers have to attenuate the beam to a safe level and be robust enough themselves to survive the impact. These requirements are difficult to fulfil with the very bright and intense beams produced by the LHC injectors for the high luminosity era. This paper revisits the requirements for the SPS-to-LHC transfer line collimation system and the adapted strategy to fulfill these for the LHC high luminosity operation. A possible solution for the new transfer line collimation system is presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI096
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRI097	Feasibility Studies for the Extraction of both LHC Beams from CERN SPS using a Common Kicker	842
	F.M. Velotti, W. Bartmann, C. Bracco, E. Carlier, K. Cornelis, B. Goddard, V. Kain, M. Meddahi CERN, Geneva, Switzerland
	The CERN Super Proton Synchrotron has to fulfil the demanding intensity specifications for the High Luminosity LHC (HL-LHC) era, with a doubling of the presently achieved operational beam intensity. One of the main problems to be addressed is given by impedance-driven beam instabilities. About 40 % of the total measured SPS impedance is due to the kickers, of which the extraction kickers in two of the SPS straight sections are the largest systems. A potential upgrade is explored which would strongly reduce the number of extraction kickers required in the SPS, by performing non-local extraction. In this scenario LHC Beam 1 would be kicked by the extraction kicker in SPS Long Straight Section 4 (LSS4), normally only used for Beam 2, to be extracted in LSS6. The concept and the expected performance of such a scheme are presented along with detailed simulation results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI097
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRI098	Design Studies of the Upgraded Collimation System in the SPS-to-LHC Transfer Lines	845
	A. Mereghetti, C. Bracco, F. Cerutti, B. Goddard, J. Hrivnak, V. Kain, F.L. Maciariello, M. Meddahi, G.E. Steele CERN, Geneva, Switzerland R. Appleby UMAN, Manchester, United Kingdom
	In the framework of the LHC Injectors Upgrade (LIU) Project, the collimators in the SPS-to-LHC transfer lines are presently under re-design, in order to cope with the unprecedented beam intensities and emittances required by the High Luminosity LHC (HL-LHC). Factors ruling the design phase are the robustness of the jaws on one side and, on the other side, the proton absorption and the emittance blow-up, essential for an effective protection of the equipment in the LHC injection regions and the LHC machine. In view of the new design, based on the one of the currently installed TCDI collimators and past investigations, the FLUKA Monte Carlo code is used to address these two factors. The present studies are intended to give essential feedback to the identification of viable solutions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI098
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRI100	Investigations of SPS Orbit Drifts	852
	L.N. Drøsdal, C. Bracco, K. Cornelis, B. Goddard, V. Kain, M. Meddahi, J. Wenninger CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA
	The LHC is filled from the last pre-injector, the Super Proton Synchrotron (SPS), via two 3 km long transfer lines, TI 2 and TI 8. Over the LHC injection processes, a drift of the beam trajectories has been observed in TI 2 and TI 8, requiring regular correction of the trajectories, in order to ensure clean injection into the LHC. Investigations of the trajectory variations in the transfer lines showed that the main source of short term trajectory drifts are current variations of the SPS extraction septa (MSE). The stability of the power converters has been improved, but the variations are still present and further improvements are being investigated. The stability over a longer period of time cannot be explained by this source alone. The analysis of trajectory variations shows that there are also slow variations in the SPS closed orbit at extraction. A set of SPS orbit measurements has been saved and analysed. These observations will be used together with simulations and observed field errors to locate the second source of variations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI100
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRO010	Origins of Transverse Emittance Blow-up during the LHC Energy Ramp	1021
SUSPSNE003	use link to see paper's listing under its alternate paper code
	M. Kuhn, G. Arduini, V. Kain, A. Langner, Y. Papaphilippou, M. Schaumann, R. Tomás CERN, Geneva, Switzerland
	During LHC Run 1 about 30 % of the potential peak performance was lost due to transverse emittance blow-up through the LHC cycle. Measurements indicated that the majority of the blow-up occurred during the energy ramp. Until the end of LHC Run 1 this emittance blow-up could not be eliminated. In this paper the measurements and observations of emittance growth through the ramp are summarized. Simulation results for growth due to Intra Beam Scattering will be shown and compared to measurements. A summary of investigations of other possible sources will be given and backed up with simulations where possible. Requirements for commissioning the LHC with beam in 2015 after Long Shutdown 1 to understand and control emittance blow-up will be listed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO010
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRO011	New Tools for K-modulation in the LHC	1024
	M. Kuhn, B. Dehning, V. Kain, R. Tomás, G. Trad CERN, Geneva, Switzerland
	For many applications, the precise knowledge of the beta function at a given location is essential. Several measurement techniques for optics functions are used in the LHC to provide the most suitable method for a given scenario. A new tool to run k-modulation measurements and analysis is being developed with the aim to be fully automatic and online. It will take constraints of various systems such as tune measurement precision, powering limits of the LHC superconducting circuits and limits of their quench protection systems into account. It will also provide the possibility to sinusoidally modulate the currents of the investigated quadrupoles with a predefined frequency and amplitude to increase the measurement precision further. This paper will review the advantages and limitations of k-modulation measurements in the LHC with and without sinusoidal current modulation. The used algorithms and tools will be presented and estimates on the obtainable beta function measurement precision will be given.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO011
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRO018	Prospects for the LHC Optics Measurements and Corrections at Higher Energy	1046
	R. Tomás, T. Bach, J.M. Coello de Portugal, V. Kain, M. Kuhn, A. Langner, Y.I. Levinsen, K.S.B. Li, E.H. Maclean, N. Magnin, V. Maier, M. McAteer, T. Persson, P.K. Skowroński, R. Westenberger CERN, Geneva, Switzerland E.H. Maclean JAI, Oxford, United Kingdom S.M. White BNL, Upton, Long Island, New York, USA
	LHC will resume operation in 2015 at 6.5 TeV. The higher energy allows for smaller IP beta functions, further enhancing the optics errors in the triplet quadrupoles. Moreover the uncertainty in the calibration of some quadrupoles will slightly increase due to saturation effects. The complete magnetic cycle of the LHC will take longer due to the higher energy and extended squeeze sequence. All these issues require more precise and more efficient optics measurements and corrections to guarantee the same optics quality level as in 2012 when a 7% peak beta-beating was achieved. This paper summarizes the on-going efforts for achieving faster and more accurate optics measurements and corrections.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO018
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRO068	SPS Beam Steering for LHC Extraction	2106
	E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA H. Bartosik, K. Cornelis, L.N. Drøsdal, B. Goddard, V. Kain, M. Meddahi, Y. Papaphilippou, J. Wenninger CERN, Geneva, Switzerland
	The CERN Super Proton Synchrotron accelerates beams for the Large Hadron Collider to 450 GeV. In addition it produces beams for fixed target facilities which adds complexity to the SPS operation. During the run 2012-2013 drifts of the extracted beam trajectories have been observed and lengthy optimizations in the transfer lines were performed to reduce particle losses in the LHC. The observed trajectory drifts are consistent with the measured SPS orbit drifts at extraction. While extensive studies are going on to understand, and possibly suppress, the source of such SPS orbit drifts the feasibility of an automatic beam steering towards a “golden” orbit at the extraction septa, by means of the interlocked correctors, is also being investigated. The challenges and constraints related to the implementation of such a correction in the SPS are described. Simulation results are presented and a possible operational steering strategy is proposed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO068
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRI093	Welding and Quality Control for the Consolidation of the LHC Superconducting Magnets and Circuits	2709
	S. Atieh, M. Bernardini, F.F. Bertinelli, P. Cruikshank, J.M. Dalin, G. Favre, V. Kain, D. Lombard, A. Perin, M. Pojer, G. Rasul, D. Rey, R. Rizwan, F. Savary, J.Ph. G. L. Tock CERN, Geneva, Switzerland
	The first LHC long shutdown was driven by the need to consolidate the 13 kA splices between the superconducting magnets to safely attain its center of mass design energy of 14 TeV. Access to the splices requires the opening of welded sleeves by machining. After consolidation, the sleeves are re-welded using a TIG orbital welding. The welding process has been modified from the original “as-new” installation in order to better adapt to the “as repaired” situation. The intervention has been thoroughly prepared through qualifications, organisation of teams, their training and follow-up. Quality control is based on the qualification of equipment, process and operators; the recording of production parameters; regular process audits and production witness samples; visual inspection through an official certifying body. The paper also describes welding and quality control of special intervention cases, with issues of difficult access requiring innovative solutions. This work concerns over 10 000 welds and a team of 40 engineers and technicians over a period of 18 months. The experience and lessons learnt will be applicable to similar large complex projects.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI093
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPME069	Performance Studies of the SPS Beam Dump System for HL-LHC Beams	3394
	F.M. Velotti, O. Aberle, C. Bracco, E. Carlier, F. Cerutti, K. Cornelis, L. Ducimetière, B. Goddard, V. Kain, R. Losito, C. Maglioni, M. Meddahi, F. Pasdeloup, V. Senaj, G.E. Steele CERN, Geneva, Switzerland
	The Super Proton Synchrotron (SPS) beam dump system is a concern for the planned High Luminosity LHC (HL-LHC) operation. The system has initially been designed for very different beam parameters compared to those which will reign after the completion of the LHC injectors upgrade, when the SPS will have to operate with unprecedented beam brightness. This paper describes the relevant operational and failure modes of the dump system together with the expected beam loading levels. Tracking studies are presented, considering both normal operation and failure scenarios, with particular attention on the location and level of proton losses. First FLUKA investigations and thermo-mechanical analysis of the high-energy absorber block are described
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME069
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPME175	A Beam Gas Vertex Detector for Beam Size Measurement in the LHC	3680
	P. Hopchev, V. Baglin, C. Barschel, E. Bravin, G. Bregliozzi, N. Chritin, B. Dehning, M. Ferro-Luzzi, C. Gaspar, M. Giovannozzi, R. Jacobsson, L.K. Jensen, O.R. Jones, N.J. Jurado, V. Kain, M. Kuhn, B. Luthi, P. Magagnin, R. Matev, N. Neufeld, J. Panman, M.N. Rihl, V. Salustino Guimaraes, B. Salvant, R. Veness, E. van Herwijnen CERN, Geneva, Switzerland A. Bay, F. Blanc, S. Gianì, G.J. Haefeli, T. Nakada, B. Rakotomiaramanana, O. Schneider, M. Tobin, Q.D. Veyrat, Z. Xu EPFL, Lausanne, Switzerland R. Greim, W. Karpinski, T. Kirn, S. Schael, G. Schwering, M. Wlochal, A. von Dratzig RWTH, Aachen, Germany R. Matev Sofia University St. Kliment Ohridski, Faculty of Physics, Sofia, Bulgaria
	The Beam Gas Vertex (BGV) detector is foreseen as a possible non-invasive beam size measurement instrument for the LHC and its luminosity upgrade. This technique is based on the reconstruction of beam gas interaction vertices, where the charged particles produced in inelastic beam gas interactions are measured with high-precision tracking detectors. The design studies and expected performance of the currently developed BGV prototype will be presented with an overview given of the associated vacuum, detector, and readout systems. A brief description will be given of the BGV Monte Carlo simulation application, which is based on the LHCb computing framework (Gaudi) and allows simulation studies to be performed and online event reconstruction algorithms to be developed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME175
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Abort Gap Cleaning for LHC Run 2

138

J.A. Uythoven, A. Boccardi, E. Bravin, B. Goddard, G.H. Hemelsoet, W. Höfle, D. Jacquet, V. Kain, S. Mazzoni, M. Meddahi, D. Valuch
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA

To minimize the beam losses at the moment of an LHC beam dump the 3 μs long abort gap should contain as few particles as possible. Its population can be minimised by abort gap cleaning using the LHC transverse damper system. The LHC Run 1 experience is briefly recalled; changes foreseen for the LHC Run 2 are presented. They include improvements in the observation of the abort gap population and the mechanism to decide if cleaning is required, changes to the hardware of the transverse dampers to reduce the detrimental effect on the luminosity lifetime and proposed changes to the applied cleaning algorithms.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO031

Export •

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

MOPRI096

The New Transfer Line Collimation System for the LHC High Luminosity Era

839

V. Kain, C. Bracco, B. Goddard, F.L. Maciariello, M. Meddahi, A. Mereghetti, G.E. Steele, F.M. Velotti
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA

A set of passive absorbers is located at the end of each of the 3 km long injection lines to protect the LHC in case of failures during the extraction process from the LHC’s last pre-injector or the beam transfer itself. In case of an erroneous extraction, the absorbers have to attenuate the beam to a safe level and be robust enough themselves to survive the impact. These requirements are difficult to fulfil with the very bright and intense beams produced by the LHC injectors for the high luminosity era. This paper revisits the requirements for the SPS-to-LHC transfer line collimation system and the adapted strategy to fulfill these for the LHC high luminosity operation. A possible solution for the new transfer line collimation system is presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI096

Export •

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

MOPRI097

Feasibility Studies for the Extraction of both LHC Beams from CERN SPS using a Common Kicker

842

F.M. Velotti, W. Bartmann, C. Bracco, E. Carlier, K. Cornelis, B. Goddard, V. Kain, M. Meddahi
CERN, Geneva, Switzerland

The CERN Super Proton Synchrotron has to fulfil the demanding intensity specifications for the High Luminosity LHC (HL-LHC) era, with a doubling of the presently achieved operational beam intensity. One of the main problems to be addressed is given by impedance-driven beam instabilities. About 40 % of the total measured SPS impedance is due to the kickers, of which the extraction kickers in two of the SPS straight sections are the largest systems. A potential upgrade is explored which would strongly reduce the number of extraction kickers required in the SPS, by performing non-local extraction. In this scenario LHC Beam 1 would be kicked by the extraction kicker in SPS Long Straight Section 4 (LSS4), normally only used for Beam 2, to be extracted in LSS6. The concept and the expected performance of such a scheme are presented along with detailed simulation results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI097

Export •

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

MOPRI098

Design Studies of the Upgraded Collimation System in the SPS-to-LHC Transfer Lines

845

A. Mereghetti, C. Bracco, F. Cerutti, B. Goddard, J. Hrivnak, V. Kain, F.L. Maciariello, M. Meddahi, G.E. Steele
CERN, Geneva, Switzerland
R. Appleby
UMAN, Manchester, United Kingdom

In the framework of the LHC Injectors Upgrade (LIU) Project, the collimators in the SPS-to-LHC transfer lines are presently under re-design, in order to cope with the unprecedented beam intensities and emittances required by the High Luminosity LHC (HL-LHC). Factors ruling the design phase are the robustness of the jaws on one side and, on the other side, the proton absorption and the emittance blow-up, essential for an effective protection of the equipment in the LHC injection regions and the LHC machine. In view of the new design, based on the one of the currently installed TCDI collimators and past investigations, the FLUKA Monte Carlo code is used to address these two factors. The present studies are intended to give essential feedback to the identification of viable solutions.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI098

Export •

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

MOPRI100

Investigations of SPS Orbit Drifts

852

L.N. Drøsdal, C. Bracco, K. Cornelis, B. Goddard, V. Kain, M. Meddahi, J. Wenninger
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA

The LHC is filled from the last pre-injector, the Super Proton Synchrotron (SPS), via two 3 km long transfer lines, TI 2 and TI 8. Over the LHC injection processes, a drift of the beam trajectories has been observed in TI 2 and TI 8, requiring regular correction of the trajectories, in order to ensure clean injection into the LHC. Investigations of the trajectory variations in the transfer lines showed that the main source of short term trajectory drifts are current variations of the SPS extraction septa (MSE). The stability of the power converters has been improved, but the variations are still present and further improvements are being investigated. The stability over a longer period of time cannot be explained by this source alone. The analysis of trajectory variations shows that there are also slow variations in the SPS closed orbit at extraction. A set of SPS orbit measurements has been saved and analysed. These observations will be used together with simulations and observed field errors to locate the second source of variations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI100

Export •

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

TUPRO010

Origins of Transverse Emittance Blow-up during the LHC Energy Ramp

1021

SUSPSNE003

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

M. Kuhn, G. Arduini, V. Kain, A. Langner, Y. Papaphilippou, M. Schaumann, R. Tomás
CERN, Geneva, Switzerland

During LHC Run 1 about 30 % of the potential peak performance was lost due to transverse emittance blow-up through the LHC cycle. Measurements indicated that the majority of the blow-up occurred during the energy ramp. Until the end of LHC Run 1 this emittance blow-up could not be eliminated. In this paper the measurements and observations of emittance growth through the ramp are summarized. Simulation results for growth due to Intra Beam Scattering will be shown and compared to measurements. A summary of investigations of other possible sources will be given and backed up with simulations where possible. Requirements for commissioning the LHC with beam in 2015 after Long Shutdown 1 to understand and control emittance blow-up will be listed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO010

Export •

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

TUPRO011

New Tools for K-modulation in the LHC

1024

M. Kuhn, B. Dehning, V. Kain, R. Tomás, G. Trad
CERN, Geneva, Switzerland

For many applications, the precise knowledge of the beta function at a given location is essential. Several measurement techniques for optics functions are used in the LHC to provide the most suitable method for a given scenario. A new tool to run k-modulation measurements and analysis is being developed with the aim to be fully automatic and online. It will take constraints of various systems such as tune measurement precision, powering limits of the LHC superconducting circuits and limits of their quench protection systems into account. It will also provide the possibility to sinusoidally modulate the currents of the investigated quadrupoles with a predefined frequency and amplitude to increase the measurement precision further. This paper will review the advantages and limitations of k-modulation measurements in the LHC with and without sinusoidal current modulation. The used algorithms and tools will be presented and estimates on the obtainable beta function measurement precision will be given.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO011

Export •

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

TUPRO018

Prospects for the LHC Optics Measurements and Corrections at Higher Energy

1046

R. Tomás, T. Bach, J.M. Coello de Portugal, V. Kain, M. Kuhn, A. Langner, Y.I. Levinsen, K.S.B. Li, E.H. Maclean, N. Magnin, V. Maier, M. McAteer, T. Persson, P.K. Skowroński, R. Westenberger
CERN, Geneva, Switzerland
E.H. Maclean
JAI, Oxford, United Kingdom
S.M. White
BNL, Upton, Long Island, New York, USA

LHC will resume operation in 2015 at 6.5 TeV. The higher energy allows for smaller IP beta functions, further enhancing the optics errors in the triplet quadrupoles. Moreover the uncertainty in the calibration of some quadrupoles will slightly increase due to saturation effects. The complete magnetic cycle of the LHC will take longer due to the higher energy and extended squeeze sequence. All these issues require more precise and more efficient optics measurements and corrections to guarantee the same optics quality level as in 2012 when a 7% peak beta-beating was achieved. This paper summarizes the on-going efforts for achieving faster and more accurate optics measurements and corrections.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO018

Export •

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

WEPRO068

SPS Beam Steering for LHC Extraction

2106

E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA
H. Bartosik, K. Cornelis, L.N. Drøsdal, B. Goddard, V. Kain, M. Meddahi, Y. Papaphilippou, J. Wenninger
CERN, Geneva, Switzerland

The CERN Super Proton Synchrotron accelerates beams for the Large Hadron Collider to 450 GeV. In addition it produces beams for fixed target facilities which adds complexity to the SPS operation. During the run 2012-2013 drifts of the extracted beam trajectories have been observed and lengthy optimizations in the transfer lines were performed to reduce particle losses in the LHC. The observed trajectory drifts are consistent with the measured SPS orbit drifts at extraction. While extensive studies are going on to understand, and possibly suppress, the source of such SPS orbit drifts the feasibility of an automatic beam steering towards a “golden” orbit at the extraction septa, by means of the interlocked correctors, is also being investigated. The challenges and constraints related to the implementation of such a correction in the SPS are described. Simulation results are presented and a possible operational steering strategy is proposed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO068

Export •

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

WEPRI093

Welding and Quality Control for the Consolidation of the LHC Superconducting Magnets and Circuits

2709

S. Atieh, M. Bernardini, F.F. Bertinelli, P. Cruikshank, J.M. Dalin, G. Favre, V. Kain, D. Lombard, A. Perin, M. Pojer, G. Rasul, D. Rey, R. Rizwan, F. Savary, J.Ph. G. L. Tock
CERN, Geneva, Switzerland

The first LHC long shutdown was driven by the need to consolidate the 13 kA splices between the superconducting magnets to safely attain its center of mass design energy of 14 TeV. Access to the splices requires the opening of welded sleeves by machining. After consolidation, the sleeves are re-welded using a TIG orbital welding. The welding process has been modified from the original “as-new” installation in order to better adapt to the “as repaired” situation. The intervention has been thoroughly prepared through qualifications, organisation of teams, their training and follow-up. Quality control is based on the qualification of equipment, process and operators; the recording of production parameters; regular process audits and production witness samples; visual inspection through an official certifying body. The paper also describes welding and quality control of special intervention cases, with issues of difficult access requiring innovative solutions. This work concerns over 10 000 welds and a team of 40 engineers and technicians over a period of 18 months. The experience and lessons learnt will be applicable to similar large complex projects.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI093

Export •

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

THPME069

Performance Studies of the SPS Beam Dump System for HL-LHC Beams

3394

F.M. Velotti, O. Aberle, C. Bracco, E. Carlier, F. Cerutti, K. Cornelis, L. Ducimetière, B. Goddard, V. Kain, R. Losito, C. Maglioni, M. Meddahi, F. Pasdeloup, V. Senaj, G.E. Steele
CERN, Geneva, Switzerland

The Super Proton Synchrotron (SPS) beam dump system is a concern for the planned High Luminosity LHC (HL-LHC) operation. The system has initially been designed for very different beam parameters compared to those which will reign after the completion of the LHC injectors upgrade, when the SPS will have to operate with unprecedented beam brightness. This paper describes the relevant operational and failure modes of the dump system together with the expected beam loading levels. Tracking studies are presented, considering both normal operation and failure scenarios, with particular attention on the location and level of proton losses. First FLUKA investigations and thermo-mechanical analysis of the high-energy absorber block are described

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME069

Export •

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

THPME175

A Beam Gas Vertex Detector for Beam Size Measurement in the LHC

3680

P. Hopchev, V. Baglin, C. Barschel, E. Bravin, G. Bregliozzi, N. Chritin, B. Dehning, M. Ferro-Luzzi, C. Gaspar, M. Giovannozzi, R. Jacobsson, L.K. Jensen, O.R. Jones, N.J. Jurado, V. Kain, M. Kuhn, B. Luthi, P. Magagnin, R. Matev, N. Neufeld, J. Panman, M.N. Rihl, V. Salustino Guimaraes, B. Salvant, R. Veness, E. van Herwijnen
CERN, Geneva, Switzerland
A. Bay, F. Blanc, S. Gianì, G.J. Haefeli, T. Nakada, B. Rakotomiaramanana, O. Schneider, M. Tobin, Q.D. Veyrat, Z. Xu
EPFL, Lausanne, Switzerland
R. Greim, W. Karpinski, T. Kirn, S. Schael, G. Schwering, M. Wlochal, A. von Dratzig
RWTH, Aachen, Germany
R. Matev
Sofia University St. Kliment Ohridski, Faculty of Physics, Sofia, Bulgaria

The Beam Gas Vertex (BGV) detector is foreseen as a possible non-invasive beam size measurement instrument for the LHC and its luminosity upgrade. This technique is based on the reconstruction of beam gas interaction vertices, where the charged particles produced in inelastic beam gas interactions are measured with high-precision tracking detectors. The design studies and expected performance of the currently developed BGV prototype will be presented with an overview given of the associated vacuum, detector, and readout systems. A brief description will be given of the BGV Monte Carlo simulation application, which is based on the LHCb computing framework (Gaudi) and allows simulation studies to be performed and online event reconstruction algorithms to be developed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME175

Export •

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