IPAC2014 - List of Authors (Langner, A.)

Paper	Title	Page
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
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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
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TUPRO062	Improvements in the Optics Measurement Resolution for the LHC	1177
	A. Langner, R. Tomás CERN, Geneva, Switzerland
	Optics measurement algorithms which are based on the measurement of beam position monitor (BPM) turn-by-turn data are currently being improved in preparation for the commissioning of the LHC at higher energy. The turn-by-turn data of one BPM may be used more than once, but the implied correlations were not considered in the final error bar. In this paper the error propagation including correlations is studied for the statistical part of the uncertainty. The confidence level of the measurement is investigated analytically and with simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO062
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THPRO080	The FiDeL Model at 7 TeV	3069
	N. Aquilina, M. Giovannozzi, P. Hagen, M. Lamont, A. Langner, E. Todesco, R. Tomás, J. Wenninger CERN, Geneva, Switzerland N.J. Sammut University of Malta, Information and Communication Technology, Msida, Malta
	After the long shut down of 2013-2014, the LHC energy will be pushed toward 7 TeV. In this range of energy, the main magnets will enter a new regime. For this reason, this paper will present a detailed study of the performance of the FiDeL model that could be critical for the operation in 2015. In particular this paper will study the saturation component and its precision in the model, together with the hysteresis error. The effect of these two components and their errors on the beta-beating is also given. Furthermore, an estimate of the dynamic effects visible in the tune and chromaticity will be presented for the 7 TeV operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO080
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

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)

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)

TUPRO062

Improvements in the Optics Measurement Resolution for the LHC

1177

A. Langner, R. Tomás
CERN, Geneva, Switzerland

Optics measurement algorithms which are based on the measurement of beam position monitor (BPM) turn-by-turn data are currently being improved in preparation for the commissioning of the LHC at higher energy. The turn-by-turn data of one BPM may be used more than once, but the implied correlations were not considered in the final error bar. In this paper the error propagation including correlations is studied for the statistical part of the uncertainty. The confidence level of the measurement is investigated analytically and with simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO062

Export •

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

THPRO080

The FiDeL Model at 7 TeV

3069

N. Aquilina, M. Giovannozzi, P. Hagen, M. Lamont, A. Langner, E. Todesco, R. Tomás, J. Wenninger
CERN, Geneva, Switzerland
N.J. Sammut
University of Malta, Information and Communication Technology, Msida, Malta

After the long shut down of 2013-2014, the LHC energy will be pushed toward 7 TeV. In this range of energy, the main magnets will enter a new regime. For this reason, this paper will present a detailed study of the performance of the FiDeL model that could be critical for the operation in 2015. In particular this paper will study the saturation component and its precision in the model, together with the hysteresis error. The effect of these two components and their errors on the beta-beating is also given. Furthermore, an estimate of the dynamic effects visible in the tune and chromaticity will be presented for the 7 TeV operation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO080

Export •

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