IPAC2014 - List of Authors (Papaphilippou, Y.)

Paper	Title	Page
MOPRI109	High-Power Proton-Synchrotron Collimation Studies	879
	A. Alekou, Y. Papaphilippou CERN, Geneva, Switzerland D. Spitzbart TU Vienna, Wien, Austria
	The High-Power Proton-Synchrotron (HP-PS) will be delivering a 2 MW proton beam to a fixed target in order to produce neutrinos within the LAGUNA-LBNO project. A mechanical collimation system is essential to prevent lost particles from hitting the super-feric dipoles of the HP-PS ring and to also limit the equipment irradiation close to the beam. This paper presents how the efficiency of the HP-PS collimator system is optimised with respect to the change of the collimators’ thickness, material and beam halo size.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI109
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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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TUPME025	Progress on Low Emittance Tuning for the CLIC Damping Rings	1404
	J. Alabau-Gonzalvo, H. Bartosik, Y. Papaphilippou CERN, Geneva, Switzerland
	In the frame of the CLIC main Damping Ring a study on the sensitivity of the lattice to different sources of misalignment is presented. The minimum equilibrium emittance is simulated and analytically estimated under dipole and quadrupole rolls, and quadrupole and sextupole vertical offsets. The result of this study establishes alignment tolerances to preserve the vertical emittance below the design value (1 pm·rad). Non-linear dynamics studies have been done to determine the dynamic aperture in the presence of misalignments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME025
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TUPME026	TMCI Thresholds for LHC Single Bunches in the CERN-SPS and Comparison with Simulations	1407
	H. Bartosik, G. Iadarola, Y. Papaphilippou, G. Rumolo, B. Salvant, C. Zannini CERN, Geneva, Switzerland
	At the beginning of 2013 an extensive measurement campaign was carried out at the SPS in order to determine the Transverse Mode Coupling Instability thresholds of LHC-type bunches in a wide range of intensities and longitudinal emittances. The measurements were performed in two different configurations of machine optics (nominal and low gamma transition) with the goal to characterize the differences in behavior and performance. The purpose of this paper is to describe in detail the measurement procedure and results, as well as the comparison of the experimental data with HEADTAIL simulations based on the latest SPS impedance model. Beside the impedances of the resistive wall, the beam position monitors (BPMs), the RF cavities, and the flanges, an advanced model of the impedance of the kicker magnets is included, which are found to play a major role in the definition of the stability region of the LHC-type bunches in the two optics configurations studied.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME026
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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
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THPRO076	Frequency Maps Analysis of Tracking and Experimental Data for the SLS Storage Ring	3056
	P. Zisopoulos, F. Antoniou, Y. Papaphilippou CERN, Geneva, Switzerland A. Streun PSI, Villigen PSI, Switzerland V.G. Ziemann Uppsala University, Uppsala, Sweden
	Frequency Maps Analysis (FMA) has been widely used in beam dynamics in order to study dynamical aspects of the particles linear and non-linear motion, such as optics functions distortion, coupling, tune-shift and resonances. In this paper, FMA is employed to explore the dynamics of models of the Swiss Light Source (SLS) storage ring and compare them with measured turn by turn (TxT) position data. In particular, a method is proposed for estimating the momentum spread using synchrotron sidebands of the Fourier spectrum of the TxT data.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO076
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THPME068	Optics Design of the High-power Proton Synchrotron for LAGUNA-LBNO	3391
	Y. Papaphilippou, J. Alabau-Gonzalvo, A. Alekou, F. Antoniou, I. Efthymiopoulos, R. Steerenberg CERN, Geneva, Switzerland
	Funding: Work supported by EC/FP7 grant 284518 The prospects for future high-power proton beams for producing neutrinos at CERN within the LAGUNA-LBNO study, include the design of a 2 MW High-Power Pro- ton Synchrotron (HP-PS). In this paper, the optics design of the ring is reviewed, comprising Negative Momentum Compaction (NMC) arc cells and quadrupole triplet long straight sections, flexible enough to achieve the constraints imposed mainly by different beam transfer equipment and processes. A global tunability study is undertaken includ- ing aperture and magnet parameter considerations. Basic correction systems are specified and their impact to beam dynamics including dynamic aperture is finally evaluated.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME068
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

High-Power Proton-Synchrotron Collimation Studies

879

A. Alekou, Y. Papaphilippou
CERN, Geneva, Switzerland
D. Spitzbart
TU Vienna, Wien, Austria

The High-Power Proton-Synchrotron (HP-PS) will be delivering a 2 MW proton beam to a fixed target in order to produce neutrinos within the LAGUNA-LBNO project. A mechanical collimation system is essential to prevent lost particles from hitting the super-feric dipoles of the HP-PS ring and to also limit the equipment irradiation close to the beam. This paper presents how the efficiency of the HP-PS collimator system is optimised with respect to the change of the collimators’ thickness, material and beam halo size.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI109

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)

TUPME025

Progress on Low Emittance Tuning for the CLIC Damping Rings

1404

J. Alabau-Gonzalvo, H. Bartosik, Y. Papaphilippou
CERN, Geneva, Switzerland

In the frame of the CLIC main Damping Ring a study on the sensitivity of the lattice to different sources of misalignment is presented. The minimum equilibrium emittance is simulated and analytically estimated under dipole and quadrupole rolls, and quadrupole and sextupole vertical offsets. The result of this study establishes alignment tolerances to preserve the vertical emittance below the design value (1 pm·rad). Non-linear dynamics studies have been done to determine the dynamic aperture in the presence of misalignments.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME025

Export •

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

TUPME026

TMCI Thresholds for LHC Single Bunches in the CERN-SPS and Comparison with Simulations

1407

H. Bartosik, G. Iadarola, Y. Papaphilippou, G. Rumolo, B. Salvant, C. Zannini
CERN, Geneva, Switzerland

At the beginning of 2013 an extensive measurement campaign was carried out at the SPS in order to determine the Transverse Mode Coupling Instability thresholds of LHC-type bunches in a wide range of intensities and longitudinal emittances. The measurements were performed in two different configurations of machine optics (nominal and low gamma transition) with the goal to characterize the differences in behavior and performance. The purpose of this paper is to describe in detail the measurement procedure and results, as well as the comparison of the experimental data with HEADTAIL simulations based on the latest SPS impedance model. Beside the impedances of the resistive wall, the beam position monitors (BPMs), the RF cavities, and the flanges, an advanced model of the impedance of the kicker magnets is included, which are found to play a major role in the definition of the stability region of the LHC-type bunches in the two optics configurations studied.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME026

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)

THPRO076

Frequency Maps Analysis of Tracking and Experimental Data for the SLS Storage Ring

3056

P. Zisopoulos, F. Antoniou, Y. Papaphilippou
CERN, Geneva, Switzerland
A. Streun
PSI, Villigen PSI, Switzerland
V.G. Ziemann
Uppsala University, Uppsala, Sweden

Frequency Maps Analysis (FMA) has been widely used in beam dynamics in order to study dynamical aspects of the particles linear and non-linear motion, such as optics functions distortion, coupling, tune-shift and resonances. In this paper, FMA is employed to explore the dynamics of models of the Swiss Light Source (SLS) storage ring and compare them with measured turn by turn (TxT) position data. In particular, a method is proposed for estimating the momentum spread using synchrotron sidebands of the Fourier spectrum of the TxT data.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO076

Export •

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

THPME068

Optics Design of the High-power Proton Synchrotron for LAGUNA-LBNO

3391

Y. Papaphilippou, J. Alabau-Gonzalvo, A. Alekou, F. Antoniou, I. Efthymiopoulos, R. Steerenberg
CERN, Geneva, Switzerland

Funding: Work supported by EC/FP7 grant 284518
The prospects for future high-power proton beams for producing neutrinos at CERN within the LAGUNA-LBNO study, include the design of a 2 MW High-Power Pro- ton Synchrotron (HP-PS). In this paper, the optics design of the ring is reviewed, comprising Negative Momentum Compaction (NMC) arc cells and quadrupole triplet long straight sections, flexible enough to achieve the constraints imposed mainly by different beam transfer equipment and processes. A global tunability study is undertaken includ- ing aperture and magnet parameter considerations. Basic correction systems are specified and their impact to beam dynamics including dynamic aperture is finally evaluated.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME068

Export •

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