IPAC2013 - List of Authors (Papaphilippou, Y.)

Paper

Title

Page

Beam Transfer Systems for the LAGUNA-LBNO Long Baseline Neutrino Beam from the CERN SPS

395

B. Goddard, W. Bartmann, I. Efthymiopoulos, Y. Papaphilippou, A.S. Parfenova
CERN, Geneva, Switzerland

For the Long Baseline neutrino facility under study at CERN (LAGUNA-LBNO) it is initially planned to extract a 400 GeV beam from the second long straight section in the SPS into the existing transfer channel TT20 leading to the North Area experimental zone, to a new target aligned with a far detector in Finland. In a second phase a new High-Power Proton Synchrotron (HPPS) accelerator is proposed, to give a 2 MW beam at about 50 GeV on the same target. In this paper the beam transfer systems required for the project are outlined, including the new sections of transfer line between the SPL, HPPS and SPS, and from the SPS to the target, and also the injection and extraction systems in the long straight section of the HPPS. The feasibility of a 4 GeV H⁻ injection system is discussed.

MOPFI060

Beam Transfer to LHC with the Low Gamma-transition SPS Optics

419

G. Vanbavinckhove, W. Bartmann, H. Bartosik, C. Bracco, L.N. Drøsdal, B. Goddard, V. Kain, M. Meddahi, V. Mertens, Y. Papaphilippou, J.A. Uythoven, J. Wenninger
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, USA

A new low gamma-transition optics with a lower integer tune, was introduced in the SPS to improve beam stability at high intensity. For transferring the beam to the LHC, the extraction bumps, extraction kickers and transfer lines needed to be adapted to the new optics. In particular, the transfer lines were re-matched and re-commissioned with the new optics. The first operational results are discussed for the SPS extraction, the transfer lines and the LHC injection. A detailed comparison is presented between the old and the new optics of the trajectories, dispersion, losses and other performance aspects.

MOPWO025

Optics and Protection of the Injection and Extraction Regions of the CLIC Damping Rings

939

R. Apsimon, B. Balhan, M.J. Barnes, J. Borburgh, B. Goddard, Y. Papaphilippou, J.A. Uythoven
CERN, Geneva, Switzerland

The optics design of the injection and extraction regions for the CLIC damping rings is presented. The design defines the parameters for the kicker magnets and septa in these regions and has been optimised to minimise the length of the insertions within the parameter space of the system. Failure modes of the injection and extraction elements are identified and their severity assessed. Protection elements for the injection and extraction regions are optimised based on the conclusions of the failure mode analysis.

MOPWO033

Analysis of LHC Transfer Line Trajectory Drifts

960

L.N. Drøsdal, W. Bartmann, H. Bartosik, C. Bracco, B. Goddard, V. Kain, Y. Papaphilippou, J.A. Uythoven, G. Vanbavinckhove, J. Wenninger
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, USA

The LHC is filled from the SPS via two 3km long transfer lines. In the first years of LHC operation large trajectory variations were discovered. The sources of bunch-by-bunch and shot-by-shot trajectory variations had been identified and improved by the 2012 LHC run. The origins of the longer term drifts were however still unclear and significant time was spent correcting the trajectories. In the last part of the 2012 run the optics in the SPS was changed to lower transition energy. Trajectory stability and correction frequency will be compared between before and after the optics change in the SPS. The sources of the variations have now been identified and will be discussed in this paper. Remedies for operation after the long shutdown will be proposed.

TUPME034

Experimental Studies for Future LHC Beams in the SPS

1652

H. Bartosik, T. Argyropoulos, T. Bohl, S. Cettour-Cave, J.F. Esteban Müller, W. Höfle, G. Iadarola, Y. Papaphilippou, G. Rumolo, B. Salvant, F. Schmidt, E.N. Shaposhnikova, H. Timko
CERN, Geneva, Switzerland
A.Y. Molodozhentsev
KEK, Ibaraki, Japan

The High Luminosity LHC (HL-LHC) project requires significantly higher beam intensity than presently accessible in the LHC injector chain. The aim of the LHC injectors upgrade project (LIU) is to prepare the CERN accelerators for the future needs of the LHC. Therefore a series of machine studies with high brightness beams were performed, assessing the present performance reach and identifying remaining limitations. Of particular concern are beam loading and longitudinal instabilities at high energy, space charge for beams with 50ns bunch spacing and electron cloud effects for beams with 25ns bunch spacing. This paper provides a summary of the performed studies, that have been possible thanks to the implementation of the SPS low gamma-transition optics.

TUPME042

The SPS as an Ultra-low Emittance Damping Ring Test Facility for CLIC

1661

Y. Papaphilippou, R. Corsini, L.R. Evans
CERN, Geneva, Switzerland

In view of the plans for a future electron/positron linear collider based on the CLIC technology, an ultra-low emittance damping ring test facility is proposed, using the CERN SPS. Optics modification, required wiggler length and characteristics, energy and RF parameters are presented in order to reach CLIC performance requirements, including the effect of Intrabeam Scattering. Considerations about the necessary injected beam characteristics, its production and transfer through the existing CERN accelerator complex are also discussed.

TUPME045

Turn-by-turn Measurements in the KEK-ATF

1664

Y. Renier, Y. Papaphilippou, R. Tomás, M. Wendt
CERN, Geneva, Switzerland
N. Eddy
Fermilab, Batavia, USA
K. Kubo, S. Kuroda, T. Naito, T. Okugi, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

The ATF damping ring has been upgraded with new read-out electronics for the beam position monitors (BPM), capable to acquire the beam orbits on a turn-by-turn basis, as well as in a high resolution averaging mode. The new BPM system allows to improve optic corrections and to achieve an even smaller vertical emittance (<2pm). Experimental results are presented based on turn-by-turn beam orbit measurements in the ring, for estimating the beta functions and dispersion along the lattice. A fast method to measure spectral line amplitude in a few turns is also presented, including the evaluation of chromaticity.

TUPME046

Performance of SPS Low Transition Energy Optics for LHC Ion Beams

1667

F. Antoniou, G. Arduini, H. Bartosik, T. Bohl, S. Cettour Cave, K. Cornelis, D. Manglunki, Y. Papaphilippou
CERN, Geneva, Switzerland

An optics with low transition energy has been developed in the SPS for removing intensity limitations of the LHC proton beam and has become operational towards the second part of the 2012 LHC proton run. This optics was also used for filling the LHC with lead ions during the p/Pb run of the beginning of 2013. The impact of this optics in the performance of the LHC ion beam is studied here, especially with respect to collective effects, at the SPS injection energy. In particular, the potential gain of the increased beam sizes provided by this optics, with respect to losses and emittance blow up due to space-charge and Intrabeam Scattering (IBS) is evaluated. The measured lifetime is compared with the one provided by the Touschek effect and its interplay with RF noise is studied. The models are supported by measurements in the SPS and in the LHC flat bottom.

WEXB101

Optics Optimization for Reducing Collective Effects and Raising Instability Thresholds in Lepton and Hadron Rings

2033

Y. Papaphilippou, F. Antoniou, H. Bartosik
CERN, Geneva, Switzerland

This paper covers recent progress in the design of optics solutions to minimize collective effects such as beam instabilities, intra-beam scattering or space charge in hadron and lepton rings. The necessary steps are reviewed for designing the optics of high-intensity and high-brightness synchrotrons but also ultra-low emittance lepton storage rings, whose performance is strongly dominated by collective effects. Particular emphasis is given to proposed and existing designs illustrated by simulations and beam measurements.

Slides WEXB101 [24.511 MB]

WEPEA053

Progress with the Upgrade of the SPS for the HL-LHC Era

2624

B. Goddard, T. Argyropoulos, W. Bartmann, H. Bartosik, T. Bohl, F. Caspers, K. Cornelis, H. Damerau, L.N. Drøsdal, L. Ducimetière, J.F. Esteban Müller, R. Garoby, M. Gourber-Pace, W. Höfle, G. Iadarola, L.K. Jensen, V. Kain, R. Losito, M. Meddahi, A. Mereghetti, V. Mertens, Ö. Mete, E. Montesinos, Y. Papaphilippou, G. Rumolo, B. Salvant, E.N. Shaposhnikova, M. Taborelli, H. Timko, F.M. Velotti
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, USA

The demanding beam performance requirements of the HL-LHC project translate into a set of requirements and upgrade paths for the LHC injector complex. In this paper the performance requirements for the SPS and the known limitations are reviewed in the light of the 2012 operational experience. The various SPS upgrades in progress and still under consideration are described, in addition to the machine studies and simulations performed in 2012. The expected machine performance reach is estimated on the basis of the present knowledge, and the remaining decisions that still need to be made concerning upgrade options are detailed.

WEPEA056

Design and Beam Measurements of Modified Fast Extraction Schemes in the CERN PS for Installing a Dummy Septum to Mitigate Ring Irradiation

2633

C. Hernalsteens, H. Bartosik, L.N. Drøsdal, S.S. Gilardoni, M. Giovannozzi, A. Lachaize, Y. Papaphilippou, A. Ulsroed
CERN, Geneva, Switzerland

The proposed Multi-Turn Extraction (MTE) for the CERN PS allows to reduce the overall extraction losses for high intensity beams. The required longitudinal structure of the proton beam induces unavoidable beam losses at the magnetic extraction septum. The installation of a dummy septum with an appropriate shielding has been proposed to localise losses and to shadow the magnetic septum. Such a device, located in the extraction region, imposes tight constraints on the available beam aperture. Modified extraction schemes have been proposed and in this paper they will be presented and discussed in detail together with the measured performance.

WEPEA060

Plans for the Upgrade of CERN's Heavy Ion Complex

2645

D. Manglunki, M. E. Angoletta, H. Bartosik, A. Blas, D. Bodart, M.A. Bodendorfer, T. Bohl, J. Borburgh, E. Carlier, J.-M. Cravero, H. Damerau, L. Ducimetière, A. Findlay, R. Garoby, S.S. Gilardoni, B. Goddard, S. Hancock, E.B. Holzer, J.M. Jowett, T. Kramer, D. Kuchler, A.M. Lombardi, Y. Papaphilippou, S. Pasinelli, R. Scrivens, G. Tranquille
CERN, Geneva, Switzerland

To reach a luminosity higher than 6×10²⁷ Hz/cm² for Pb-Pb collisions, as expected by the ALICE experiment after its upgrade during the 2nd Long LHC Shutdown (LS2), several upgrades will have to be performed in the CERN accelerator complex, from the source to the LHC itself. This paper first details the present limitations and then describes the strategy for the different machines in the ion injector chain. Both filling schemes and possible hardware upgrades are discussed.

WEPEA061

The First LHC p-Pb run: Performance of the Heavy Ion Production Complex

2648

D. Manglunki, M. E. Angoletta, H. Bartosik, G. Bellodi, A. Blas, M.A. Bodendorfer, T. Bohl, C. Carli, E. Carlier, S. Cettour Cave, K. Cornelis, H. Damerau, A. Findlay, S.S. Gilardoni, S. Hancock, J.M. Jowett, D. Kuchler, M. O'Neil, Y. Papaphilippou, S. Pasinelli, R. Scrivens, G. Tranquille, B. Vandorpe, U. Wehrle, J. Wenninger
CERN, Geneva, Switzerland

TThe first LHC proton-ion run took place in January-February 2013; it was the first extension to the collider programme, as this mode was not included in the design report. This paper presents the performance of the heavy ion and proton production complex, and details the issues encountered, in particular the creation of the same bunch pattern in both beams.

WEPEA064

SixTrack-Fluka Active Coupling for the Upgrade of the SPS Scrapers

2657

A. Mereghetti, F. Cerutti, R. De Maria, B. Goddard, V. Kain, M. Meddahi, Ö. Mete, Y. Papaphilippou, D. Pastor Sinuela, V. Vlachoudis
CERN, Geneva, Switzerland
R. Appleby
UMAN, Manchester, United Kingdom

The LHC Injectors Upgrade (LIU) Project aims at upgrading the systems in the LHC injection chain, to reliably deliver the beams required by the High-Luminosity LHC (HL-LHC). Essential for the clean injection into the LHC, the SPS scrapers are one of the important systems under revision. In order to take into account of the effect of betatron and longitudinal beam dynamics on energy deposition patterns, and nuclear and Coulomb scattering in the absorbing medium onto loss patterns, the SixTrack and Fluka codes have been coupled, profiting from the best of the refined physical models they respectively embed. The coupling envisages an active exchange of tracked particles between the two codes at each turn, and an on-line aperture check in SixTrack, in order to estimate the local cleaning inefficiency of the system. Knob-like, time-dependent strengths have been implemented in SixTrack, since the designed scraper system foresees the use of a magnetic bump. The study is intended to assess the robustness of the proposed scraper as well as its effectiveness with respect to the desired performance.

WEPEA067

Beam Optics Measurements through Turn by turn Beam Position Data in the SLS

2663

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

Refined Fourier analysis of turn-by-turn (TBT) transverse position data measurements can be used for determining several beam properties of a ring, such as transverse tunes, optics functions, phases, chromatic properties and coupling. In particular, the Numerical Analysis of Fundamental Frequencies (NAFF) algorithm is used to analyze TBT data from the Swiss Light Source (SLS) storage ring in order to estimate on and off-momentum beam characteristics. Of particular interest is the potential of using the full position information within one turn in order to measure beam optics properties.

THOBB102

Beam Coupling Impedance Localization Technique Validation and Measurements in the CERN Machines

3106

N. Biancacci, G. Arduini, T. Argyropoulos, H. Bartosik, R. Calaga, K. Cornelis, S.S. Gilardoni, N. Mounet, E. Métral, Y. Papaphilippou, S. Persichelli, G. Rumolo, B. Salvant, G. Sterbini, R. Tomás, R. Wasef
CERN, Geneva, Switzerland
M. Migliorati, L. Palumbo
URLS, Rome, Italy

The beam coupling impedance could lead to limitations in beam brightness and quality, and therefore it needs accurate quantification and continuous monitoring in order to detect and mitigate high impedance sources. In the CERN machines, for example, kickers and collimators are expected to be the main contributors to the total imaginary part of the transverse impedance. In order to detect the other sources, a beam based measurement was developed: from the variation of betatron phase beating with intensity, it is possible to detect the locations of main impedance sources. In this work we present the application of the method with beam measurements in the CERN PS, SPS and LHC.

Slides THOBB102 [7.224 MB]

THPFI056

Design Study for a Future LAGUNA-LBNO Long-baseline Neutrino Facility at CERN

3418

I. Efthymiopoulos, J. Alabau-Gonzalvo, A. Alekou, F. Antoniou, M. Benedikt, M. Calviani, A. Ferrari, R. Garoby, F. Gerigk, S.S. Gilardoni, B. Goddard, A. Kosmicki, C. Lazaridis, J.A. Osborne, Y. Papaphilippou, A.S. Parfenova, E.N. Shaposhnikova, R. Steerenberg, P. Velten, H. Vincke
CERN, Geneva, Switzerland

A design study for a long baseline neutrino oscillation experiment (LBNO) with a new conventional neutrino beamline facility (CN2PY) at CERN was initiated in September 2011, supported by EU/FP7 funds. The beam will be aimed at a next generation deep-underground neutrino observatory located at the Pyhasalmi (Finland) mine at a distance of 2300 km. In an initial phase the CN2PY facility will use a 400 GeV beam extracted from SPS up to a maximum power of 750 kW, and in a second phase a 2 MW beam of about 50 GeV produced by a new High-Power Proton Synchrotron accelerator using the LP-SPL as injector also under design. The paper will focus on the design challenges of this MW-class facility and on the optimization studies of the secondary beam elements (target and horns) to produce a neutrino beam spectrum that matches best the experimental requirements for neutrino flavor oscillations and CP-violation tests. The challenges and bottlenecks in the existing CERN accelerator complex to produce the high-intensity beams foreseen for this facility at the initial phase are discussed.

THPWO080

Operational Performance of the LHC Proton Beams with the SPS Low Transition Energy Optics

3945

Y. Papaphilippou, G. Arduini, T. Argyropoulos, W. Bartmann, H. Bartosik, T. Bohl, C. Bracco, S. Cettour-Cave, K. Cornelis, L.N. Drøsdal, J.F. Esteban Müller, B. Goddard, A. Guerrero, W. Höfle, V. Kain, G. Rumolo, B. Salvant, E.N. Shaposhnikova, H. Timko, D. Valuch, G. Vanbavinckhove, J. Wenninger
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, USA

An optics in the SPS with lower integer tunes (20 versus 26) was proposed and introduced in machine studies since 2010, as a measure for increasing transverse and longitudinal instability thresholds, especially at low energy, for the LHC proton beams. After two years of machine studies and careful optimisation, the new “Q20” optics became operational in September 2012 and steadily delivered beam to the LHC until the end of the run. This paper reviews the operational performance of the Q20 optics with respect to transverse and longitudinal beam characteristics in the SPS, enabling high brightness beams injected into the LHC. Aspects of longitudinal beam stability, transmission, high-energy orbit control and beam transfer are discussed.

THPWO081

Design Options of a High-power Proton Synchrotron for LAGUNA-LBNO

3948

Y. Papaphilippou, J. Alabau-Gonzalvo, A. Alekou, F. Antoniou, M. Benedikt, I. Efthymiopoulos, R. Garoby, F. Gerigk, B. Goddard, C. Lazaridis, A.S. Parfenova, E.N. Shaposhnikova, R. Steerenberg
CERN, Geneva, Switzerland

Design studies have been initiated at CERN, exploring the prospects of future high-power proton beams for producing neutrinos, within the LAGUNA-LBNO project. These studies include the design of a 2 MW high-power proton synchrotron (HP-PS) using the LP-SPL as injector. This paper resumes the design options under study in order to reach this high power, and their implications regarding layout, magnet technology beam loss control and RF considerations. Optics optimization studies are also presented including beam transfer and collimation considerations.

Paper	Title	Page
MOPFI051	Beam Transfer Systems for the LAGUNA-LBNO Long Baseline Neutrino Beam from the CERN SPS	395
	B. Goddard, W. Bartmann, I. Efthymiopoulos, Y. Papaphilippou, A.S. Parfenova CERN, Geneva, Switzerland
	For the Long Baseline neutrino facility under study at CERN (LAGUNA-LBNO) it is initially planned to extract a 400 GeV beam from the second long straight section in the SPS into the existing transfer channel TT20 leading to the North Area experimental zone, to a new target aligned with a far detector in Finland. In a second phase a new High-Power Proton Synchrotron (HPPS) accelerator is proposed, to give a 2 MW beam at about 50 GeV on the same target. In this paper the beam transfer systems required for the project are outlined, including the new sections of transfer line between the SPL, HPPS and SPS, and from the SPS to the target, and also the injection and extraction systems in the long straight section of the HPPS. The feasibility of a 4 GeV H⁻ injection system is discussed.

MOPFI060	Beam Transfer to LHC with the Low Gamma-transition SPS Optics	419
	G. Vanbavinckhove, W. Bartmann, H. Bartosik, C. Bracco, L.N. Drøsdal, B. Goddard, V. Kain, M. Meddahi, V. Mertens, Y. Papaphilippou, J.A. Uythoven, J. Wenninger CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, USA
	A new low gamma-transition optics with a lower integer tune, was introduced in the SPS to improve beam stability at high intensity. For transferring the beam to the LHC, the extraction bumps, extraction kickers and transfer lines needed to be adapted to the new optics. In particular, the transfer lines were re-matched and re-commissioned with the new optics. The first operational results are discussed for the SPS extraction, the transfer lines and the LHC injection. A detailed comparison is presented between the old and the new optics of the trajectories, dispersion, losses and other performance aspects.

MOPWO025	Optics and Protection of the Injection and Extraction Regions of the CLIC Damping Rings	939
	R. Apsimon, B. Balhan, M.J. Barnes, J. Borburgh, B. Goddard, Y. Papaphilippou, J.A. Uythoven CERN, Geneva, Switzerland
	The optics design of the injection and extraction regions for the CLIC damping rings is presented. The design defines the parameters for the kicker magnets and septa in these regions and has been optimised to minimise the length of the insertions within the parameter space of the system. Failure modes of the injection and extraction elements are identified and their severity assessed. Protection elements for the injection and extraction regions are optimised based on the conclusions of the failure mode analysis.

MOPWO033	Analysis of LHC Transfer Line Trajectory Drifts	960
	L.N. Drøsdal, W. Bartmann, H. Bartosik, C. Bracco, B. Goddard, V. Kain, Y. Papaphilippou, J.A. Uythoven, G. Vanbavinckhove, J. Wenninger CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, USA
	The LHC is filled from the SPS via two 3km long transfer lines. In the first years of LHC operation large trajectory variations were discovered. The sources of bunch-by-bunch and shot-by-shot trajectory variations had been identified and improved by the 2012 LHC run. The origins of the longer term drifts were however still unclear and significant time was spent correcting the trajectories. In the last part of the 2012 run the optics in the SPS was changed to lower transition energy. Trajectory stability and correction frequency will be compared between before and after the optics change in the SPS. The sources of the variations have now been identified and will be discussed in this paper. Remedies for operation after the long shutdown will be proposed.

TUPME034	Experimental Studies for Future LHC Beams in the SPS	1652
	H. Bartosik, T. Argyropoulos, T. Bohl, S. Cettour-Cave, J.F. Esteban Müller, W. Höfle, G. Iadarola, Y. Papaphilippou, G. Rumolo, B. Salvant, F. Schmidt, E.N. Shaposhnikova, H. Timko CERN, Geneva, Switzerland A.Y. Molodozhentsev KEK, Ibaraki, Japan
	The High Luminosity LHC (HL-LHC) project requires significantly higher beam intensity than presently accessible in the LHC injector chain. The aim of the LHC injectors upgrade project (LIU) is to prepare the CERN accelerators for the future needs of the LHC. Therefore a series of machine studies with high brightness beams were performed, assessing the present performance reach and identifying remaining limitations. Of particular concern are beam loading and longitudinal instabilities at high energy, space charge for beams with 50ns bunch spacing and electron cloud effects for beams with 25ns bunch spacing. This paper provides a summary of the performed studies, that have been possible thanks to the implementation of the SPS low gamma-transition optics.

TUPME042	The SPS as an Ultra-low Emittance Damping Ring Test Facility for CLIC	1661
	Y. Papaphilippou, R. Corsini, L.R. Evans CERN, Geneva, Switzerland
	In view of the plans for a future electron/positron linear collider based on the CLIC technology, an ultra-low emittance damping ring test facility is proposed, using the CERN SPS. Optics modification, required wiggler length and characteristics, energy and RF parameters are presented in order to reach CLIC performance requirements, including the effect of Intrabeam Scattering. Considerations about the necessary injected beam characteristics, its production and transfer through the existing CERN accelerator complex are also discussed.

TUPME045	Turn-by-turn Measurements in the KEK-ATF	1664
	Y. Renier, Y. Papaphilippou, R. Tomás, M. Wendt CERN, Geneva, Switzerland N. Eddy Fermilab, Batavia, USA K. Kubo, S. Kuroda, T. Naito, T. Okugi, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	The ATF damping ring has been upgraded with new read-out electronics for the beam position monitors (BPM), capable to acquire the beam orbits on a turn-by-turn basis, as well as in a high resolution averaging mode. The new BPM system allows to improve optic corrections and to achieve an even smaller vertical emittance (<2pm). Experimental results are presented based on turn-by-turn beam orbit measurements in the ring, for estimating the beta functions and dispersion along the lattice. A fast method to measure spectral line amplitude in a few turns is also presented, including the evaluation of chromaticity.

TUPME046	Performance of SPS Low Transition Energy Optics for LHC Ion Beams	1667
	F. Antoniou, G. Arduini, H. Bartosik, T. Bohl, S. Cettour Cave, K. Cornelis, D. Manglunki, Y. Papaphilippou CERN, Geneva, Switzerland
	An optics with low transition energy has been developed in the SPS for removing intensity limitations of the LHC proton beam and has become operational towards the second part of the 2012 LHC proton run. This optics was also used for filling the LHC with lead ions during the p/Pb run of the beginning of 2013. The impact of this optics in the performance of the LHC ion beam is studied here, especially with respect to collective effects, at the SPS injection energy. In particular, the potential gain of the increased beam sizes provided by this optics, with respect to losses and emittance blow up due to space-charge and Intrabeam Scattering (IBS) is evaluated. The measured lifetime is compared with the one provided by the Touschek effect and its interplay with RF noise is studied. The models are supported by measurements in the SPS and in the LHC flat bottom.

WEXB101	Optics Optimization for Reducing Collective Effects and Raising Instability Thresholds in Lepton and Hadron Rings	2033
	Y. Papaphilippou, F. Antoniou, H. Bartosik CERN, Geneva, Switzerland
	This paper covers recent progress in the design of optics solutions to minimize collective effects such as beam instabilities, intra-beam scattering or space charge in hadron and lepton rings. The necessary steps are reviewed for designing the optics of high-intensity and high-brightness synchrotrons but also ultra-low emittance lepton storage rings, whose performance is strongly dominated by collective effects. Particular emphasis is given to proposed and existing designs illustrated by simulations and beam measurements.
	Slides WEXB101 [24.511 MB]

WEPEA053	Progress with the Upgrade of the SPS for the HL-LHC Era	2624
	B. Goddard, T. Argyropoulos, W. Bartmann, H. Bartosik, T. Bohl, F. Caspers, K. Cornelis, H. Damerau, L.N. Drøsdal, L. Ducimetière, J.F. Esteban Müller, R. Garoby, M. Gourber-Pace, W. Höfle, G. Iadarola, L.K. Jensen, V. Kain, R. Losito, M. Meddahi, A. Mereghetti, V. Mertens, Ö. Mete, E. Montesinos, Y. Papaphilippou, G. Rumolo, B. Salvant, E.N. Shaposhnikova, M. Taborelli, H. Timko, F.M. Velotti CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, USA
	The demanding beam performance requirements of the HL-LHC project translate into a set of requirements and upgrade paths for the LHC injector complex. In this paper the performance requirements for the SPS and the known limitations are reviewed in the light of the 2012 operational experience. The various SPS upgrades in progress and still under consideration are described, in addition to the machine studies and simulations performed in 2012. The expected machine performance reach is estimated on the basis of the present knowledge, and the remaining decisions that still need to be made concerning upgrade options are detailed.

WEPEA056	Design and Beam Measurements of Modified Fast Extraction Schemes in the CERN PS for Installing a Dummy Septum to Mitigate Ring Irradiation	2633
	C. Hernalsteens, H. Bartosik, L.N. Drøsdal, S.S. Gilardoni, M. Giovannozzi, A. Lachaize, Y. Papaphilippou, A. Ulsroed CERN, Geneva, Switzerland
	The proposed Multi-Turn Extraction (MTE) for the CERN PS allows to reduce the overall extraction losses for high intensity beams. The required longitudinal structure of the proton beam induces unavoidable beam losses at the magnetic extraction septum. The installation of a dummy septum with an appropriate shielding has been proposed to localise losses and to shadow the magnetic septum. Such a device, located in the extraction region, imposes tight constraints on the available beam aperture. Modified extraction schemes have been proposed and in this paper they will be presented and discussed in detail together with the measured performance.

WEPEA060	Plans for the Upgrade of CERN's Heavy Ion Complex	2645
	D. Manglunki, M. E. Angoletta, H. Bartosik, A. Blas, D. Bodart, M.A. Bodendorfer, T. Bohl, J. Borburgh, E. Carlier, J.-M. Cravero, H. Damerau, L. Ducimetière, A. Findlay, R. Garoby, S.S. Gilardoni, B. Goddard, S. Hancock, E.B. Holzer, J.M. Jowett, T. Kramer, D. Kuchler, A.M. Lombardi, Y. Papaphilippou, S. Pasinelli, R. Scrivens, G. Tranquille CERN, Geneva, Switzerland
	To reach a luminosity higher than 6×10²⁷ Hz/cm² for Pb-Pb collisions, as expected by the ALICE experiment after its upgrade during the 2nd Long LHC Shutdown (LS2), several upgrades will have to be performed in the CERN accelerator complex, from the source to the LHC itself. This paper first details the present limitations and then describes the strategy for the different machines in the ion injector chain. Both filling schemes and possible hardware upgrades are discussed.

WEPEA061	The First LHC p-Pb run: Performance of the Heavy Ion Production Complex	2648
	D. Manglunki, M. E. Angoletta, H. Bartosik, G. Bellodi, A. Blas, M.A. Bodendorfer, T. Bohl, C. Carli, E. Carlier, S. Cettour Cave, K. Cornelis, H. Damerau, A. Findlay, S.S. Gilardoni, S. Hancock, J.M. Jowett, D. Kuchler, M. O'Neil, Y. Papaphilippou, S. Pasinelli, R. Scrivens, G. Tranquille, B. Vandorpe, U. Wehrle, J. Wenninger CERN, Geneva, Switzerland
	TThe first LHC proton-ion run took place in January-February 2013; it was the first extension to the collider programme, as this mode was not included in the design report. This paper presents the performance of the heavy ion and proton production complex, and details the issues encountered, in particular the creation of the same bunch pattern in both beams.

WEPEA064	SixTrack-Fluka Active Coupling for the Upgrade of the SPS Scrapers	2657
	A. Mereghetti, F. Cerutti, R. De Maria, B. Goddard, V. Kain, M. Meddahi, Ö. Mete, Y. Papaphilippou, D. Pastor Sinuela, V. Vlachoudis CERN, Geneva, Switzerland R. Appleby UMAN, Manchester, United Kingdom
	The LHC Injectors Upgrade (LIU) Project aims at upgrading the systems in the LHC injection chain, to reliably deliver the beams required by the High-Luminosity LHC (HL-LHC). Essential for the clean injection into the LHC, the SPS scrapers are one of the important systems under revision. In order to take into account of the effect of betatron and longitudinal beam dynamics on energy deposition patterns, and nuclear and Coulomb scattering in the absorbing medium onto loss patterns, the SixTrack and Fluka codes have been coupled, profiting from the best of the refined physical models they respectively embed. The coupling envisages an active exchange of tracked particles between the two codes at each turn, and an on-line aperture check in SixTrack, in order to estimate the local cleaning inefficiency of the system. Knob-like, time-dependent strengths have been implemented in SixTrack, since the designed scraper system foresees the use of a magnetic bump. The study is intended to assess the robustness of the proposed scraper as well as its effectiveness with respect to the desired performance.

WEPEA067	Beam Optics Measurements through Turn by turn Beam Position Data in the SLS	2663
	P. Zisopoulos, Y. Papaphilippou CERN, Geneva, Switzerland A. Streun PSI, Villigen PSI, Switzerland V.G. Ziemann Uppsala University, Uppsala, Sweden
	Refined Fourier analysis of turn-by-turn (TBT) transverse position data measurements can be used for determining several beam properties of a ring, such as transverse tunes, optics functions, phases, chromatic properties and coupling. In particular, the Numerical Analysis of Fundamental Frequencies (NAFF) algorithm is used to analyze TBT data from the Swiss Light Source (SLS) storage ring in order to estimate on and off-momentum beam characteristics. Of particular interest is the potential of using the full position information within one turn in order to measure beam optics properties.

THOBB102	Beam Coupling Impedance Localization Technique Validation and Measurements in the CERN Machines	3106
	N. Biancacci, G. Arduini, T. Argyropoulos, H. Bartosik, R. Calaga, K. Cornelis, S.S. Gilardoni, N. Mounet, E. Métral, Y. Papaphilippou, S. Persichelli, G. Rumolo, B. Salvant, G. Sterbini, R. Tomás, R. Wasef CERN, Geneva, Switzerland M. Migliorati, L. Palumbo URLS, Rome, Italy
	The beam coupling impedance could lead to limitations in beam brightness and quality, and therefore it needs accurate quantification and continuous monitoring in order to detect and mitigate high impedance sources. In the CERN machines, for example, kickers and collimators are expected to be the main contributors to the total imaginary part of the transverse impedance. In order to detect the other sources, a beam based measurement was developed: from the variation of betatron phase beating with intensity, it is possible to detect the locations of main impedance sources. In this work we present the application of the method with beam measurements in the CERN PS, SPS and LHC.
	Slides THOBB102 [7.224 MB]

THPFI056	Design Study for a Future LAGUNA-LBNO Long-baseline Neutrino Facility at CERN	3418
	I. Efthymiopoulos, J. Alabau-Gonzalvo, A. Alekou, F. Antoniou, M. Benedikt, M. Calviani, A. Ferrari, R. Garoby, F. Gerigk, S.S. Gilardoni, B. Goddard, A. Kosmicki, C. Lazaridis, J.A. Osborne, Y. Papaphilippou, A.S. Parfenova, E.N. Shaposhnikova, R. Steerenberg, P. Velten, H. Vincke CERN, Geneva, Switzerland
	A design study for a long baseline neutrino oscillation experiment (LBNO) with a new conventional neutrino beamline facility (CN2PY) at CERN was initiated in September 2011, supported by EU/FP7 funds. The beam will be aimed at a next generation deep-underground neutrino observatory located at the Pyhasalmi (Finland) mine at a distance of 2300 km. In an initial phase the CN2PY facility will use a 400 GeV beam extracted from SPS up to a maximum power of 750 kW, and in a second phase a 2 MW beam of about 50 GeV produced by a new High-Power Proton Synchrotron accelerator using the LP-SPL as injector also under design. The paper will focus on the design challenges of this MW-class facility and on the optimization studies of the secondary beam elements (target and horns) to produce a neutrino beam spectrum that matches best the experimental requirements for neutrino flavor oscillations and CP-violation tests. The challenges and bottlenecks in the existing CERN accelerator complex to produce the high-intensity beams foreseen for this facility at the initial phase are discussed.

THPWO080	Operational Performance of the LHC Proton Beams with the SPS Low Transition Energy Optics	3945
	Y. Papaphilippou, G. Arduini, T. Argyropoulos, W. Bartmann, H. Bartosik, T. Bohl, C. Bracco, S. Cettour-Cave, K. Cornelis, L.N. Drøsdal, J.F. Esteban Müller, B. Goddard, A. Guerrero, W. Höfle, V. Kain, G. Rumolo, B. Salvant, E.N. Shaposhnikova, H. Timko, D. Valuch, G. Vanbavinckhove, J. Wenninger CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, USA
	An optics in the SPS with lower integer tunes (20 versus 26) was proposed and introduced in machine studies since 2010, as a measure for increasing transverse and longitudinal instability thresholds, especially at low energy, for the LHC proton beams. After two years of machine studies and careful optimisation, the new “Q20” optics became operational in September 2012 and steadily delivered beam to the LHC until the end of the run. This paper reviews the operational performance of the Q20 optics with respect to transverse and longitudinal beam characteristics in the SPS, enabling high brightness beams injected into the LHC. Aspects of longitudinal beam stability, transmission, high-energy orbit control and beam transfer are discussed.

THPWO081	Design Options of a High-power Proton Synchrotron for LAGUNA-LBNO	3948
	Y. Papaphilippou, J. Alabau-Gonzalvo, A. Alekou, F. Antoniou, M. Benedikt, I. Efthymiopoulos, R. Garoby, F. Gerigk, B. Goddard, C. Lazaridis, A.S. Parfenova, E.N. Shaposhnikova, R. Steerenberg CERN, Geneva, Switzerland
	Design studies have been initiated at CERN, exploring the prospects of future high-power proton beams for producing neutrinos, within the LAGUNA-LBNO project. These studies include the design of a 2 MW high-power proton synchrotron (HP-PS) using the LP-SPL as injector. This paper resumes the design options under study in order to reach this high power, and their implications regarding layout, magnet technology beam loss control and RF considerations. Optics optimization studies are also presented including beam transfer and collimation considerations.