IPAC2017 - List of Authors (Trad, G.)

Paper	Title	Page
MOPAB110	Comparison of Transverse Emittance Measurements in the LHC	377
	M. Hostettler, R. Alemany-Fernández, F. Alessio, M. Ferro-Luzzi, K. Fuchsberger, G. Iadarola, R. Matev, S. Papadopoulou, Y. Papaphilippou, G. Papotti, G. Trad CERN, Geneva, Switzerland F. Antoniou The University of Liverpool, Liverpool, United Kingdom G.R. Coombs University of Glasgow, Glasgow, United Kingdom T.B. Hadavizadeh Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	Transverse emittance measurement in a collider is of crucial importance for understanding beam dynamics observations and evaluating the machine performance. Devices measuring the beam emittance face the challenge of dealing with considerable systematic errors that can compromise the quality of the measurement. Having different instruments or techniques that provide beam size estimations in order to compare the outcome and give an unbiased value of the emittance is very important in a collider. The comparison of the different results is as well very useful to identify possible problems in a given equipment which could remain unnoticed if such device is the only source of emittance reconstruction. In the LHC several of these instruments and techniques are available; wire scanners, synchrotron light monitors, emittance reconstruction from transverse convolved beam sizes extracted from luminosity scans at the LHC collision points and from beam-gas imaging in the vertex detector of the LHCb experiment. Those systems are briefly presented in this paper together with the comparison of the emittances reconstructed by each of them during physics production over the 2016 LHC run.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB110
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MOPAB130	Cross-Calibration of the LHC Transverse Beam-Profile Monitors	437
	R. Alemany-Fernández, F. Alessio, A. Alexopoulos, C. Barschel, F.S. Carlier, J.M. Coello de Portugal, M. Ferro-Luzzi, A. Garcia-Tabares, M. Hostettler, O. Karacheban, E.H. Maclean, R. Matev, T. Persson, P.K. Skowroński, R. Tomás, G. Trad, S. Vlachos, B. Würkner CERN, Geneva, Switzerland G.R. Coombs EPFL, Lausanne, Switzerland T.B. Hadavizadeh Oxford University, Physics Department, Oxford, Oxon, United Kingdom M. Hofer TU Vienna, Wien, Austria L. van Riesen-Haupt University of Oxford, Oxford, United Kingdom
	Calibration of a transverse beam profile monitor is of fundamental importance to guarantee the best possible accuracy and reliability of the instrument over time. In LHC the calibration standard for transverse-profile measurements are the wire scanners. Other profile monitors such as beam synchrotron light telescopes and interferometers are calibrated with respect to them. Additional information about single-bunch sizes can be obtained from beam-gas imaging in the LHCb vertex detector, from the transverse convolved beam sizes extracted from luminosity scans at the collision points, and from the evolution of the luminous-region parameters as reconstructed by ATLAS and CMS inner tracker detectors during such scans. For the first time in LHC, a dedicated cross-calibration of all the above-mentioned systems was carried out with beam in 2016. Additionally, dedicated optics measurements were also performed in order to determine with the highest possible accuracy the amplitude function at the interaction points and at the position of the profile monitors. Results of these measurements are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB130
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TUOAB2	First Observation of the LHC Beam Halo Using a Synchrotron Radiation Coronagraph	1244
	T.M. Mitsuhashi KEK, Ibaraki, Japan E. Bravin, F. Roncarolo, G. Trad CERN, Geneva, Switzerland
	A test coronagraph for the observation of beam halo has been installed in the Synchrotron radiation monitor line LHCB2 in 2015. This coronagraph is commissioned with LHC operation at 450GeV (injection energy). After some optical testing of the coronagraph with visible Synchrotron radiation in B2, we try to observe artificially-made beam halo. The beam halo of 10^-3 order of magnitude against the beam core is excited by the kicker of the transverse damper. We have succeeded to observe a diffraction noise free image of beam halo. The effect of beam collimator is also observed. Reduction of beam halo intensity was found nicely proportional to the simultaneously-recorded beam loss.
	Slides TUOAB2 [8.302 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUOAB2
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Paper

Title

Page

Comparison of Transverse Emittance Measurements in the LHC

377

M. Hostettler, R. Alemany-Fernández, F. Alessio, M. Ferro-Luzzi, K. Fuchsberger, G. Iadarola, R. Matev, S. Papadopoulou, Y. Papaphilippou, G. Papotti, G. Trad
CERN, Geneva, Switzerland
F. Antoniou
The University of Liverpool, Liverpool, United Kingdom
G.R. Coombs
University of Glasgow, Glasgow, United Kingdom
T.B. Hadavizadeh
Oxford University, Physics Department, Oxford, Oxon, United Kingdom

Transverse emittance measurement in a collider is of crucial importance for understanding beam dynamics observations and evaluating the machine performance. Devices measuring the beam emittance face the challenge of dealing with considerable systematic errors that can compromise the quality of the measurement. Having different instruments or techniques that provide beam size estimations in order to compare the outcome and give an unbiased value of the emittance is very important in a collider. The comparison of the different results is as well very useful to identify possible problems in a given equipment which could remain unnoticed if such device is the only source of emittance reconstruction. In the LHC several of these instruments and techniques are available; wire scanners, synchrotron light monitors, emittance reconstruction from transverse convolved beam sizes extracted from luminosity scans at the LHC collision points and from beam-gas imaging in the vertex detector of the LHCb experiment. Those systems are briefly presented in this paper together with the comparison of the emittances reconstructed by each of them during physics production over the 2016 LHC run.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB110

Export •

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

MOPAB130

Cross-Calibration of the LHC Transverse Beam-Profile Monitors

437

R. Alemany-Fernández, F. Alessio, A. Alexopoulos, C. Barschel, F.S. Carlier, J.M. Coello de Portugal, M. Ferro-Luzzi, A. Garcia-Tabares, M. Hostettler, O. Karacheban, E.H. Maclean, R. Matev, T. Persson, P.K. Skowroński, R. Tomás, G. Trad, S. Vlachos, B. Würkner
CERN, Geneva, Switzerland
G.R. Coombs
EPFL, Lausanne, Switzerland
T.B. Hadavizadeh
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
M. Hofer
TU Vienna, Wien, Austria
L. van Riesen-Haupt
University of Oxford, Oxford, United Kingdom

Calibration of a transverse beam profile monitor is of fundamental importance to guarantee the best possible accuracy and reliability of the instrument over time. In LHC the calibration standard for transverse-profile measurements are the wire scanners. Other profile monitors such as beam synchrotron light telescopes and interferometers are calibrated with respect to them. Additional information about single-bunch sizes can be obtained from beam-gas imaging in the LHCb vertex detector, from the transverse convolved beam sizes extracted from luminosity scans at the collision points, and from the evolution of the luminous-region parameters as reconstructed by ATLAS and CMS inner tracker detectors during such scans. For the first time in LHC, a dedicated cross-calibration of all the above-mentioned systems was carried out with beam in 2016. Additionally, dedicated optics measurements were also performed in order to determine with the highest possible accuracy the amplitude function at the interaction points and at the position of the profile monitors. Results of these measurements are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB130

Export •

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

TUOAB2

First Observation of the LHC Beam Halo Using a Synchrotron Radiation Coronagraph

1244

T.M. Mitsuhashi
KEK, Ibaraki, Japan
E. Bravin, F. Roncarolo, G. Trad
CERN, Geneva, Switzerland

A test coronagraph for the observation of beam halo has been installed in the Synchrotron radiation monitor line LHCB2 in 2015. This coronagraph is commissioned with LHC operation at 450GeV (injection energy). After some optical testing of the coronagraph with visible Synchrotron radiation in B2, we try to observe artificially-made beam halo. The beam halo of 10^-3 order of magnitude against the beam core is excited by the kicker of the transverse damper. We have succeeded to observe a diffraction noise free image of beam halo. The effect of beam collimator is also observed. Reduction of beam halo intensity was found nicely proportional to the simultaneously-recorded beam loss.

Slides TUOAB2 [8.302 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUOAB2

Export •

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