IPAC2017 - List of Authors (Alemany-Fernandez, R.)

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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MOPAB131	Transverse Emittance Measurements Using LHCb's Beam-Gas Interactions	441
	T.B. Hadavizadeh Oxford University, Physics Department, Oxford, Oxon, United Kingdom R. Alemany-Fernández, F. Alessio, C. Barschel, G.R. Coombs, M. Ferro-Luzzi, R. Matev CERN, Geneva, Switzerland
	Measurements of the transverse beam emittance are of great importance at particle accelerators such as the LHC in order to monitor, understand and improve the performance of the machine. A number of profile monitors at the LHC are capable of measuring the transverse emittance from a range of different processes including wire scanners and beam synchrotron light monitors, each having advantages and shortcomings. It is possible additionally to measure the beam profiles using interaction vertices reconstructed in LHCb's vertex locator (Velo). Interactions between colliding beam particles and between beam particles and residual gas nuclei are used to build up a picture of the beam profiles. To guarantee the reliability and quality of the different emittance measurements, a dedicated cross-calibration was performed during a machine development period in October 2016. The results obtained with the LHCb Velo during this cross-calibration are presented here.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB131
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TUPVA013	Lifetime of Asymmetric Colliding Beams in the LHC	2067
	J.M. Jowett, R. Alemany-Fernández, M.A. Jebramcik, T. Mertens, M. Schaumann CERN, Geneva, Switzerland
	In the 2013 proton-nucleus (p-Pb) run of the LHC, the lifetime of the lead beam was significantly shorter than could be accounted for by luminosity burn-off. These effects were observed at a lower level in 2016 and studied in more detail. The beams were not only asymmetric but the differences in the bunch filling schemes between protons and Pb nuclei led to a wide variety of beam-beam interaction sequences in the bunch trains. The colliding bunches were also of different sizes. We present an analysis of the data and an interpretation in terms of theoretical models.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA013
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TUPVA014	The 2016 Proton-Nucleus Run of the LHC	2071
	J.M. Jowett, R. Alemany-Fernández, G. Baud, P. Baudrenghien, R. De Maria, R. De Maria, D. Jacquet, M.A. Jebramcik, A. Mereghetti, T. Mertens, M. Schaumann, H. Timko, M. Wendt, J. Wenninger CERN, Geneva, Switzerland
	For five of the LHC experiments the second p-Pb collision run planned in 2016 offered the opportunity to answer a range of important physics questions arising from the surprise discoveries (e.g., flow-like collective phenomena in small systems) made in earlier Pb-Pb, p-Pb and p-p runs. However the diversity of the physics and their respective capabilities led them to request very different operating conditions, in terms of collision energy, luminosity and pile-up. These appeared mutually incompatible within the available one month of operation. Nevertheless, a plan to satisfy most requirements was developed and implemented successfully. It exploited different beam lifetimes at two beam energies of 4 Z TeV and 6.5 Z TeV, a variety of luminosity sharing and bunch filling schemes, and varying beam directions. The outcome of this very complex strategy for repeated re-commissioning and operation of the LHC included the longest ever LHC fill with luminosity levelled for almost 38 h. The peak luminosity achieved exceeded the design value by a factor 7.8 and integrated luminosity substantially exceeded the experiments' requests.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA014
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TUPVA032	Beam-Gas Background Observations at LHC	2129
	S.M. Gibson Royal Holloway, University of London, Surrey, United Kingdom R. Alemany-Fernández, F. Alessio, G. Bregliozzi, H. Burkhardt, G. Corti, A. Di Mauro, M. Guthoff, A. Manousos, K.N. Sjobak, C. Yin Vallgren CERN, Geneva, Switzerland A. Alici Bologna University, Bologna, Italy S. D'Auria University of Glasgow, Glasgow, United Kingdom S.M. Gibson JAI, Egham, Surrey, United Kingdom D. Lazic BUphy, Boston, Massachusetts, USA
	Observations of beam-induced background at LHC during 2015 and 2016 are presented in this paper. The four LHC experiments use the non-colliding bunches present in the physics-filling pattern of the accelerator to trigger on beam-gas interactions. During luminosity production the LHC experiments record the beam-gas interactions using dedicated background monitors. These data are sent to the LHC control system and are used to monitor the background levels at the experiments during accelerator operation. This is a very important measurement, since poor beam-induced background conditions can seriously affect the performance of the detectors. A summary of the evolution of the background levels during 2015 and 2016 is given in these proceedings.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA032
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TUPVA128	Performance of the CERN Injector Complex and Transmission Studies into the LHC during the Second Proton-Lead Run	2395
	R. Alemany-Fernández, S.C.P. Albright, M.E. Angoletta, J. Axensalva, W. Bartmann, H. Bartosik, P. Baudrenghien, G. Bellodi, A. Blas, T. Bohl, E. Carlier, S. Cettour-Cave, K. Cornelis, H. Damerau, A. Findlay, S.S. Gilardoni, S. Hancock, A. Huschauer, M.A. Jebramcik, S. Jensen, J.M. Jowett, V. Kain, D. Küchler, A.M. Lombardi, D. Manglunki, T. Mertens, M. O'Neil, S. Pasinelli, Á. Saá Hernández, M. Schaumann, R. Scrivens, R. Steerenberg, H. Timko, V. Toivanen, G. Tranquille, F.M. Velotti, F.J.C. Wenander, J. Wenninger CERN, Geneva, Switzerland
	The LHC performance during the proton-lead run in 2016 fully relied on a permanent monitoring and systematic improvement of the beam quality in all the injectors. The beam production and characteristics are explained in this paper, together with the improvements realized during the run from the source up to the flat top of the LHC. Transmission studies from one accelerator to the next as well as beam quality evolution studies during the cycle at each accelerator, have been carried out and are summarized in this paper. In 2016, the LHC had to deliver the beams to the experiments at two different energies, 4 Z TeV and 6.5 Z TeV. The properties of the beams at these two energies are also presented
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA128
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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

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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

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MOPAB131

Transverse Emittance Measurements Using LHCb's Beam-Gas Interactions

441

T.B. Hadavizadeh
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
R. Alemany-Fernández, F. Alessio, C. Barschel, G.R. Coombs, M. Ferro-Luzzi, R. Matev
CERN, Geneva, Switzerland

Measurements of the transverse beam emittance are of great importance at particle accelerators such as the LHC in order to monitor, understand and improve the performance of the machine. A number of profile monitors at the LHC are capable of measuring the transverse emittance from a range of different processes including wire scanners and beam synchrotron light monitors, each having advantages and shortcomings. It is possible additionally to measure the beam profiles using interaction vertices reconstructed in LHCb's vertex locator (Velo). Interactions between colliding beam particles and between beam particles and residual gas nuclei are used to build up a picture of the beam profiles. To guarantee the reliability and quality of the different emittance measurements, a dedicated cross-calibration was performed during a machine development period in October 2016. The results obtained with the LHCb Velo during this cross-calibration are presented here.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB131

Export •

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

TUPVA013

Lifetime of Asymmetric Colliding Beams in the LHC

2067

J.M. Jowett, R. Alemany-Fernández, M.A. Jebramcik, T. Mertens, M. Schaumann
CERN, Geneva, Switzerland

In the 2013 proton-nucleus (p-Pb) run of the LHC, the lifetime of the lead beam was significantly shorter than could be accounted for by luminosity burn-off. These effects were observed at a lower level in 2016 and studied in more detail. The beams were not only asymmetric but the differences in the bunch filling schemes between protons and Pb nuclei led to a wide variety of beam-beam interaction sequences in the bunch trains. The colliding bunches were also of different sizes. We present an analysis of the data and an interpretation in terms of theoretical models.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA013

Export •

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

TUPVA014

The 2016 Proton-Nucleus Run of the LHC

2071

J.M. Jowett, R. Alemany-Fernández, G. Baud, P. Baudrenghien, R. De Maria, R. De Maria, D. Jacquet, M.A. Jebramcik, A. Mereghetti, T. Mertens, M. Schaumann, H. Timko, M. Wendt, J. Wenninger
CERN, Geneva, Switzerland

For five of the LHC experiments the second p-Pb collision run planned in 2016 offered the opportunity to answer a range of important physics questions arising from the surprise discoveries (e.g., flow-like collective phenomena in small systems) made in earlier Pb-Pb, p-Pb and p-p runs. However the diversity of the physics and their respective capabilities led them to request very different operating conditions, in terms of collision energy, luminosity and pile-up. These appeared mutually incompatible within the available one month of operation. Nevertheless, a plan to satisfy most requirements was developed and implemented successfully. It exploited different beam lifetimes at two beam energies of 4 Z TeV and 6.5 Z TeV, a variety of luminosity sharing and bunch filling schemes, and varying beam directions. The outcome of this very complex strategy for repeated re-commissioning and operation of the LHC included the longest ever LHC fill with luminosity levelled for almost 38 h. The peak luminosity achieved exceeded the design value by a factor 7.8 and integrated luminosity substantially exceeded the experiments' requests.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA014

Export •

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

TUPVA032

Beam-Gas Background Observations at LHC

2129

S.M. Gibson
Royal Holloway, University of London, Surrey, United Kingdom
R. Alemany-Fernández, F. Alessio, G. Bregliozzi, H. Burkhardt, G. Corti, A. Di Mauro, M. Guthoff, A. Manousos, K.N. Sjobak, C. Yin Vallgren
CERN, Geneva, Switzerland
A. Alici
Bologna University, Bologna, Italy
S. D'Auria
University of Glasgow, Glasgow, United Kingdom
S.M. Gibson
JAI, Egham, Surrey, United Kingdom
D. Lazic
BUphy, Boston, Massachusetts, USA

Observations of beam-induced background at LHC during 2015 and 2016 are presented in this paper. The four LHC experiments use the non-colliding bunches present in the physics-filling pattern of the accelerator to trigger on beam-gas interactions. During luminosity production the LHC experiments record the beam-gas interactions using dedicated background monitors. These data are sent to the LHC control system and are used to monitor the background levels at the experiments during accelerator operation. This is a very important measurement, since poor beam-induced background conditions can seriously affect the performance of the detectors. A summary of the evolution of the background levels during 2015 and 2016 is given in these proceedings.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA032

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

TUPVA128

Performance of the CERN Injector Complex and Transmission Studies into the LHC during the Second Proton-Lead Run

2395

R. Alemany-Fernández, S.C.P. Albright, M.E. Angoletta, J. Axensalva, W. Bartmann, H. Bartosik, P. Baudrenghien, G. Bellodi, A. Blas, T. Bohl, E. Carlier, S. Cettour-Cave, K. Cornelis, H. Damerau, A. Findlay, S.S. Gilardoni, S. Hancock, A. Huschauer, M.A. Jebramcik, S. Jensen, J.M. Jowett, V. Kain, D. Küchler, A.M. Lombardi, D. Manglunki, T. Mertens, M. O'Neil, S. Pasinelli, Á. Saá Hernández, M. Schaumann, R. Scrivens, R. Steerenberg, H. Timko, V. Toivanen, G. Tranquille, F.M. Velotti, F.J.C. Wenander, J. Wenninger
CERN, Geneva, Switzerland

The LHC performance during the proton-lead run in 2016 fully relied on a permanent monitoring and systematic improvement of the beam quality in all the injectors. The beam production and characteristics are explained in this paper, together with the improvements realized during the run from the source up to the flat top of the LHC. Transmission studies from one accelerator to the next as well as beam quality evolution studies during the cycle at each accelerator, have been carried out and are summarized in this paper. In 2016, the LHC had to deliver the beams to the experiments at two different energies, 4 Z TeV and 6.5 Z TeV. The properties of the beams at these two energies are also presented

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA128

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