<?xml version="1.0" encoding="UTF-8"?> <rss version="2.0" xmlns:media="http://search.yahoo.com/mrss/" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:dcterms="http://purl.org/dc/terms/" xmlns:opensearch="http://a9.com/-/spec/opensearch/1.1/"> <channel> <title>CERN Document Server</title> <link>https://cds.cern.ch</link> <description>CERN Document Server latest documents</description> <language>en</language> <pubDate>Thu, 28 Nov 2024 21:09:37 GMT</pubDate> <category></category> <generator>Invenio 1.1.3.1106-62468</generator> <ttl>360</ttl> <atom:link rel="next" href="/rss?jrec=26&amp;f=author&amp;ln=pl&amp;p=Sterbini%2C+G" /> <atom:link rel="self" href="/rss?f=author&amp;ln=pl&amp;p=Sterbini%2C+G" /> <opensearch:totalResults>122</opensearch:totalResults> <opensearch:startIndex>1</opensearch:startIndex> <opensearch:itemsPerPage>25</opensearch:itemsPerPage> <image> <url>https://cds.cern.ch/img/site_logo_rss.png</url> <title>CERN Document Server</title> <link>https://cds.cern.ch</link> </image> <atom:link rel="search" href="https://cds.cern.ch/opensearchdescription" type="application/opensearchdescription+xml" title="Content Search" /> <textInput> <title>Search </title> <description>Search this site:</description> <name>p</name> <link>https://cds.cern.ch/search</link> </textInput> <item> <title>Measurements of beam correlations induced via coupled resonance crossing in the CERN PSB</title> <link>https://cds.cern.ch/record/2913149</link> <description>Beam profile measurements in the LHC and its injector complex show heavy tails in both transverse planes. From standard profile measurements, it is not possible to determineif the underlying phase space distribution is statistically independent. A measurement campaign in the CERN PSB was carried out to introduce cross-plane dependence in bunched beams in controlled conditions, in view of characterizing the LHC operational beam distributions. The results of the measurement campaign demonstrate how heavy tails can be created via coupled resonance excitation of the lattice in the presence of space charge, in accordance with predictions from the fixed line theory. The coupled resonance introduces dependence between the different planes, which persists after the resonance excitation is removed.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lamb, Elleanor</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Asvesta, Foteini</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Franchetti, Giuliano</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bartosik, Hannes</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Seidel, Mike</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Albright, Simon</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Prebibaj, Tirsi</dc:creator> <pubDate>Fri, 11 Oct 2024 05:10:26 GMT</pubDate> <guid>https://cds.cern.ch/record/2913149</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2913149/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Xsuite: an integrated beam physics simulation framework</title> <link>https://cds.cern.ch/record/2912920</link> <description>Xsuite is a modular simulation package bringing to a single flexible and modern framework capabilities of different tools developed at CERN in the past decades notably MAD-X Sixtrack Sixtracklib COMBI and PyHEADTAIL. The suite consists of a set of Python modules (Xobjects, Xpart, Xtrack, Xcoll, Xfields, Xdeps) that can be flexibly combined together and with other accelerator-specific and general-purpose python tools to study complex simulation scenarios. Different computing platforms are supported including conventional CPUs as well as GPUs from different vendors. The code allows for symplectic modeling of the particle dynamics combined with the effect of synchrotron radiation impedances feedbacks space charge electron cloud beam-beam beamstrahlung and electron lenses. For collimation studies beam-matter interaction is simulated using the K2 scattering model or interfacing Xsuite with the BDSIM/Geant4 library and with the FLUKA code. Methods are made available to compute and optimize the accelerator lattice functions, chromatic properties and equilibrium beam sizes. By now the tool has reached a mature stage of development and is used for simulations studies by a large and diverse user community.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Iadarola, Giovanni</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Latina, Andrea</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Abramov, Andrey</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Montanari, Carlo Emilio</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Droin, Colas</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Di Croce, Davide</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Demetriadou, Despina</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Soubelet, Felix</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Van der Veken, Frederik</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Dilly, Joschua</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Paraschou, Konstantinos</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Deniau, Laurent</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mether, Lotta</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">van Riesen-Haupt, Léon</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hermes, Pascal</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kicsiny, Peter</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kruyt, Peter</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Niedermayer, Philipp</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Belanger, Philippe</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">De Maria, Riccardo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kostoglou, Sofia</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lopaciuk, Szymon</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Pieloni, Tatiana</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Prebibaj, Tirsi</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Buffat, Xavier</dc:creator> <pubDate>Wed, 09 Oct 2024 13:10:08 GMT</pubDate> <guid>https://cds.cern.ch/record/2912920</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2912920/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Emittance and luminosity monitoring and modelling for LHC Run 3</title> <link>https://cds.cern.ch/record/2912919</link> <description>A comprehensive model accurately depicts and tracks emittance and luminosity evolution in the Large Hadron Collider (LHC), considering known effects like IBS, synchrotron radiation damping, coupling and incorporating data-driven factors on emittance growth and intensity losses. Used extensively in LHC Run 2, the model is updated for compatibility with new optics and operational schemes in Run 3, featuring luminosity leveling. This paper discusses the analysis of 2022 and 2023 LHC data, exploring emittance evolution and identifying extra blow-up at injection and collision energies compared to model predictions. Examining the model's agreement with collision data provides insights into the impact of degradation mechanisms, configuration options, filling schemes, and beam types on delivered luminosity. These studies offer valuable insights into potential gains in integrated luminosity for subsequent Run 3 years.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Efthymiopoulos, Ilias</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bartosik, Hannes</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kostoglou, Sofia</dc:creator> <pubDate>Wed, 09 Oct 2024 13:10:07 GMT</pubDate> <guid>https://cds.cern.ch/record/2912919</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2912919/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Emittance growth studies due to Crab Cavity induced amplitude noise in the SPS</title> <link>https://cds.cern.ch/record/2912901</link> <description>In the context of the HL-LHC upgrade, RF Crab Cavities (CCs) are one of the key components to achieve the target integrated luminosity. Due to the increased bunch intensity, the collider will operate with a large crossing angle scheme to alleviate the long-range beam-beam effect. The CCs will counteract the geometrical luminosity reduction factor coming from the large crossing angle. Amplitude and phase noise injected from the CC low-level RF control are known to induce transverse bunch emittance growth. This contribution presents measurements of emittance growth induced by amplitude noise, performed in the CERN Super Proton Synchotron (SPS). The measured emittance growth was found to be dependent on the amplitude detuning induced by the SPS octupoles, although no dependence was predicted by the available theories and models. In this paper, the measurement results will be presented and compared with tracking simulations.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Fornara, Andrea</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Trad, Georges</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bartosik, Hannes</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Triantafyllou, Natalia</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Baudrenghien, Philippe</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Calaga, Rama</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Appleby, Robert</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kostoglou, Sofia</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Levens, Thomas</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Buffat, Xavier</dc:creator> <pubDate>Wed, 09 Oct 2024 13:09:53 GMT</pubDate> <guid>https://cds.cern.ch/record/2912901</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2912901/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Bunch-by-bunch simulations of beam-beam driven particle losses in the LHC</title> <link>https://cds.cern.ch/record/2912730</link> <description>Recent experimental measurements in the Large Hadron Collider (LHC) have shown a clear correlation between beam-beam resonance driving terms and beam losses, with a characteristic bunch-by-bunch signature. This observation creates interesting conditions to study diffusive processes. Over the past few decades, early chaos indicators, frequency map analysis and dynamic aperture studies have been commonly used to study particle stability in circular machines. However, the underlying mechanisms driving particles to large amplitudes in the presence of high order resonances is still an open question. Leveraging on years of development on particle tracking tools, this paper presents full-fledged 6-dimensional bunch-by-bunch beam loss simulations in the LHC. The computed loss rates are shown to be in agreement with experimental observations from LHC Run 3.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Belanger, Philippe</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Baartman, Rick</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kaltchev, Dobrin</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Iadarola, Giovanni</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <pubDate>Tue, 08 Oct 2024 05:55:11 GMT</pubDate> <guid>https://cds.cern.ch/record/2912730</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2912730/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Status of beam-beam studies for the high-luminosity LHC</title> <link>https://cds.cern.ch/record/2912723</link> <description>Optimizing the configuration of an operational cycle of a collider such as the LHC is a complex process, requiring various simulation studies. In particular, Dynamic Aperture (DA) simulations, based on particle tracking, serve as indispensable tools for achieving this goal. In the framework of the high-luminosity LHC (HL-LHC) studies, our primary focus lies in performing parametric beam-beam DA simulations for the critical phases of the collision process, which includes the collapse of the beam separation bump, as well as the start, and the end of the luminosity leveling. In this paper, we present the status of our ongoing studies for different optics and filling schemes, and we comment on how they could guide the orchestration of the operational settings along the luminosity leveling phase of the HL-LHC cycle.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Droin, Colas</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Efthymiopoulos, Ilias</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mounet, Nicolas</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">De Maria, Riccardo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Tomas, Rogelio</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kostoglou, Sofia</dc:creator> <pubDate>Tue, 08 Oct 2024 05:55:08 GMT</pubDate> <guid>https://cds.cern.ch/record/2912723</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2912723/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Luminosity effects due to dependent heavy-tailed beams</title> <link>https://cds.cern.ch/record/2912366</link> <description>The luminosity of particle colliders depends, among other parameters, on the transverse profiles of the colliding beams. At the LHC at CERN, heavy-tailed transverse beam distributions are typically observed in routine operation. The luminosity is usually modelled with the assumption that the 𝑥-𝑦 planes are independent (i.e. statistically uncorrelated particle distributions between the planes) in each beam. Analytical calculations show that the solution of inverting 1D heavy-tailed beam profiles to transverse 4D phase-space distributions is not unique. For a given transverse beam profile, the distributions can be dependent (i.e. statistically correlated) or independent in the transverse planes, even in the absence of machine coupling. In this work, the effect of transverse 𝑥-𝑦 dependence of the 4D phase space distribution on the luminosity of a particle collider is evaluated for heavy-tailed beams.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lamb, Elleanor</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bartosik, Hannes</dc:creator> <pubDate>Fri, 04 Oct 2024 06:52:50 GMT</pubDate> <guid>https://cds.cern.ch/record/2912366</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2912366/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Numerical methods for emittance computation from luminosity</title> <link>https://cds.cern.ch/record/2912362</link> <description>The beam transverse emittances play a critical role in high-energy colliders. Various measurement techniques are employed to measure them. In particular, the so-called luminosity emittance scans (or Van der Meer scans) are used in order to evaluate the convoluted beam emittances. This method assumes different emittances in the two planes but identical emittances in the two beams. In this paper, we propose an approach to remove this constraint. After having presented the new measurement protocol, we will discuss its potential and limits, including the statistical measurement error of the luminosity value as obtained from numerical studies.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Rufolo, Matteo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Fornara, Andrea</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lamb, Elleanor</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Giacomel, Lorenzo</dc:creator> <pubDate>Fri, 04 Oct 2024 06:52:46 GMT</pubDate> <guid>https://cds.cern.ch/record/2912362</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2912362/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Simulations and experiments for dynamic aperture studies in the LHC ion operation</title> <link>https://cds.cern.ch/record/2912191</link> <description>Dynamic Aperture (DA) studies, based on single-particle tracking simulations including important non-linear fields such as beam-beam effects, have played a crucial role in guiding the operation of the Large Hadron Collider (LHC) in proton-proton collisions. The correspondence between DA computed through simulations and the actual beam lifetime during operation has been established for proton beams through dedicated experiments at the LHC. However, such an approach has not yet been applied to the Pb ion operation of the accelerator, as the simulation tools have not been rigorously benchmarked against experimental data yet. The present paper presents the simulation studies and experimental tests performed to establish the correlation between DA and beam lifetime for ions. The main focus lies on exploring the beam-beam limit when the crossing angle is significantly reduced in all LHC experiments as compared to the nominal configuration. This approach opens the possibility to operate with reduced crossing angles or reduced $\beta^*$ within the beam-beam limit, potentially leading to an enhanced performance of the accelerator with ions.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kostoglou, Sofia</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bartosik, Hannes</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Efthymiopoulos, Ilias</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hostettler, Michi</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bruce, Roderik</dc:creator> <pubDate>Wed, 02 Oct 2024 12:55:09 GMT</pubDate> <guid>https://cds.cern.ch/record/2912191</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2912191/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Chapter 27: Beam-beam Long Range Compensation: From Concept to Validation</title> <link>https://cds.cern.ch/record/2905921</link> <description>The compensation of the long-range beam-beam interactions using DC wires is presently under study as an option for enhancing the Large Hadron Collider (LHC) performance in the framework of the High-Luminosity LHC (HL-LHC) Project. After the installation of four wire demonstrators in the LHC, a successful experimental campaign was performed, with various beam conditions and wire set-ups. In parallel, a simulation framework was established to support the experimental results in terms of the impact of the wires on dynamic aperture and thereby lifetime, for both LHC and HL-LHC.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Papaphilippou, Y</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, G</dc:creator> <pubDate>Wed, 31 Jul 2024 04:27:29 GMT</pubDate> <guid>https://cds.cern.ch/record/2905921</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2905921/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>High intensity beam dynamics assessment and challenges for HL-LHC</title> <link>https://cds.cern.ch/record/2901253</link> <description>The High Luminosity (HL-LHC) project aims to increase the integrated luminosity of CERN’s Large Hadron Collider (LHC) by an order of magnitude compared to its initial design. This requires a large increase in bunch intensity and beam brightness compared to the first LHC runs, and hence poses serious collective-effects challenges, related in particular to electron cloud, instabilities from beam-coupling impedance, and beam-beam effects. Here we present the associated constraints and the proposed mitigation measures to achieve the baseline performance of the upgraded LHC machine. We also discuss the interplay of these mitigation measures with other aspects of the accelerator, such as the physical and dynamic aperture, machine protection, magnet imperfections, optics, and the collimation system.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Rumolo, G</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Salvant, B</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mounet, N</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Tomás, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bartosik, H</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Baudrenghien, P</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bruce, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Buffat, X</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Calaga, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">De Maria, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Droin, C</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Giacomel, L</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Giovannozzi, M</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Iadarola, G</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kostoglou, S</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lindström, B</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mether, L</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Métral, E</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Papaphilippou, Y</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Redaelli, S</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Paraschou, K</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, G</dc:creator> <pubDate>Tue, 18 Jun 2024 05:49:20 GMT</pubDate> <guid>https://cds.cern.ch/record/2901253</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2901253/files/PublicationJACoW.pdf"/> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2901253/files/PublicationIOP.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Measurement of Transverse Statistical Dependence for Non-Gaussian Beam Distributions via Resonances in the CERN PSB</title> <link>https://cds.cern.ch/record/2901221</link> <description>This work addresses the origins and the effects of the statistical dependence in non-Gaussian beam distributions with the ultimate goal to identify the most representative case for tracking simulations across the CERN accelerator complex. Starting from the observation that non-Gaussian heavy-tailed transverse beam profiles can be reconstructed from 4D phase space distributions under two different conditions (statistical independence or dependence in the x-y plane), we consider space charge dominated beams interacting with the lattice nonlinear resonances to perform measurements to study the mechanisms that lead to non-Gaussian distributions. Finally, we explore the beam dynamics implications of the above hypotheses in terms of dependent loss processes across the transverse planes.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lamb, Elleanor</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Asvesta, Foteini</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bartosik, Hannes</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <pubDate>Tue, 18 Jun 2024 05:48:54 GMT</pubDate> <guid>https://cds.cern.ch/record/2901221</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2901221/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Increasing High Luminosity LHC Dynamic Aperture Using Optics Optimizations</title> <link>https://cds.cern.ch/record/2901216</link> <description>CERN’s Large Hadron Collider (LHC) is expected to operate with unprecedented beam current and brightness from the beginning of Run 4 in 2029. In the context of the High Luminosity LHC project, the baseline operational scenarios are currently being developed. They require a large octupole current and a large chromaticity throughout the entire cycle, which drives a strong reduction of dynamic aperture, in particular at injection and during the luminosity production phase. Despite being highly constrained, the LHC optics and sextupole and octupole corrector circuits still offer a few degrees of freedom that can be used to reduce resonances and the extent of the tune footprint at constant Landau damping, thereby leading to an improvement of the dynamic aperture. This contribution presents the status of the analysis that will be used to prepare the optics baseline for LHC Run 4.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">De Maria, Riccardo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Angelis, Yannis</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Droin, Colas</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kostoglou, Sofia</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Plassard, Fabien</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Tomás García, Rogelio</dc:creator> <pubDate>Tue, 18 Jun 2024 05:48:51 GMT</pubDate> <guid>https://cds.cern.ch/record/2901216</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2901216/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>LHC Upgrades in preparation of Run 3</title> <link>https://cds.cern.ch/record/2900025</link> <description>The Large Hadron Collider (LHC) Long Shutdown 2(2019–2021), following LHC Run 2, was primarily dedicated to theupgrade of the LHC Injectors but it included also a significantamount of activities aimed at consolidation of the LHC machinecomponents, removal of known limitations and initial upgrades inview of the High-Luminosity LHC (HL-LHC) to favour the intensityramp-up during Run 3 (2022–2025). An overview of the majormodifications to the accelerator and its systems is followed by asummary of the results of the superconducting magnet trainingcampaign to increase the LHC operation energy beyond the maximumvalue of 6.5 TeV reached during Run 2. The LHC configuration andthe scenarios for proton and ion operation for Run 3 are presentedconsidering the expected performance of the upgraded LHC Injectorsand the proton beam intensity limitations resulting from the heatload on the cryogenic system due to beam-induced electron cloud andimpedance.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Arduini, G</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Baglin, V</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bartosik, H</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bottura, L</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bracco, C</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bradu, B</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bregliozzi, G</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Brodzinski, K</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bruce, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Calviani, M</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Chiggiato, P</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Cruikshank, P</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Claudet, S</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Delikaris, D</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Fartoukh, S</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Garion, C</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Himmerlich, M</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hostettler, M</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Iadarola, G</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kostoglou, S</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Le Naour, S</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lechner, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lefevre, T</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mether, L</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Papaphilippou, Y</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Petit, V</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Pojer, M</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Poyet, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Redaelli, S</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Rodriguez Mateos, F</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Rumolo, G</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Salvant, B</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sanchez Galan, F</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Siemko, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Solfaroli-Camillocci, M</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, G</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Taborelli, M</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Tavian, L</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Timko, H</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Tock, J Ph</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Verweij, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Wendt, M</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Wenninger, J</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Wollmann, D</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Yin Vallgren, Ch</dc:creator> <pubDate>Fri, 07 Jun 2024 04:37:16 GMT</pubDate> <guid>https://cds.cern.ch/record/2900025</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2900025/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Measurement of emittance growth and oscillation spectrum for different damper gains (MD 9407)</title> <link>https://cds.cern.ch/record/2895148</link> <description>The procedure of an experiment aiming at studying the impact of the transverse damper gain on the beam oscillation spectrum and on the emittance growth of colliding beams is described along with the corresponding results. It is shown experimentally that the damper reduces the beam oscillation of the 50Hz harmonics cluster around 8kHz. The beneficial impact of the upgrade of the transverse damper pickup electronics on the emittance growth rate is also demonstrated.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Buffat, Xavier</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Fornara, Andrea</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Giacomel, Lorenzo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kostoglou, Sofia</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lannoy, Christophe</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mounet, Nicolas</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Radoslavova, Anna Valeri</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Valuch, Daniel</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">CERN. Geneva. ATS Department</dc:creator> <pubDate>Thu, 11 Apr 2024 09:49:17 GMT</pubDate> <dc:date xmlns:dc="http://purl.org/dc/elements/1.1/">09 Apr 2024</dc:date> <dc:source xmlns:dc="http://purl.org/dc/elements/1.1/">CERN-ACC-NOTE-2024-0007</dc:source> <guid>https://cds.cern.ch/record/2895148</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2895148/files/NoiseMD2023 (1).pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">2024</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/">0007</dc:hasVersion> </item> <item> <title>Beam-beam long range compensator mechanical demonstrator</title> <link>https://cds.cern.ch/record/2886519</link> <description>Beam-Beam Long-Range Compensators employing current-carrying wires are considered as valuable options in hadron colliders to increase dynamic aperture at small crossing angles. This paper presents a simple design proposal for application at CERN LHC. The preliminary design allows for a certain scalability of the number of modules, current flowing in the wire, and dimensions. It complies with two key requirements: (a) the use of a thin, bare metal wire that allows for movement as near to the beam as necessary while minimising interactions with beam particles and meeting the specified DC current target; and (b) a wire support that is both an electrical insulator and a thermal conductor (ceramic).A molybdenum wire, vacuum brazed on an aluminium nitride support, is proposed, and the design is conceptually proved through the realisation and extensive test of a demonstrator device. The wire brazing validation, as well as the system's heat management, which are the most critical aspects, are given particular regard.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sito, Leonardo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Rossi, Adriana</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bertarelli, Alessandro</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Accettura, Carlotta</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Carra, Federico</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Motschmann, Fritz</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Guardia Valenzuela, J</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Gentini, Luca</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Garlaschè, Marco</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Guinchard, Michael</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sacristan De Frutos, Oscar</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hoell, Stefan</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Papaphilippou, Yannis</dc:creator> <pubDate>Tue, 16 Jan 2024 05:45:23 GMT</pubDate> <guid>https://cds.cern.ch/record/2886519</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2886519/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Harmonics of 50 Hz on the beam spectrum of the Large Hadron Collider</title> <link>https://cds.cern.ch/record/2886013</link> <description>Studies of the beam spectrum of the Large Hadron Collider (LHC) have revealed the existence of harmonics of the mains frequency (50~Hz), ranging from 50~Hz to 8~kHz, in the form of transverse dipolar excitations. The restart of the LHC operation in Run 3 was accompanied by substantial improvements in the beam instrumentation. In particular, the upgrade of the transverse damper’s observation system (ADTObsBox), currently providing bunch-by-bunch and continuous position measurements, allows for the first time a systematic follow-up of the harmonics’ evolution during the run. In this paper, we present parasitic observations collected during the LHC physics operation, as well as results from dedicated experiments with the aim of providing further insights into the source of the perturbation, especially concerning the 50~Hz harmonics around 8~kHz. These tests include modifications in the operation mode of systems such as some of the Uninterruptible Power Supplies, while observing potential changes in the spectrum of the beam position data.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kostoglou, S</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bartosik, H</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, G</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Soderen, M</dc:creator> <pubDate>Wed, 10 Jan 2024 05:25:51 GMT</pubDate> <guid>https://cds.cern.ch/record/2886013</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2886013/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>High Luminosity LHC optics scenarios for Run 4</title> <link>https://cds.cern.ch/record/2886006</link> <description>Run 4 will be the first operational run of the LHC with full deployment of the upgrades from the High Luminosity (HL-LHC) project planned for 2026-2028 (Long Shutdown 3). The commissioning goals for the first run were defined to approach steadily the design beam current, while already fulfilling significant luminosity goals. Despite extensive operational experience already gained, intensity limitations due to electron cloud and/or impedance might require to further reduce beta* values from the very early stages. The paper presents various optics configurations considered under different Run4 scenarios together with their expected dynamic aperture.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">De Maria, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bruce, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Buffat, X</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Iadarola, G</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kostoglou, S</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Giovannozzi, M</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lindström, B</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mether, L</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Métral, E</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mounet, N</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Redaelli, S</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, G</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Tomás, R</dc:creator> <pubDate>Wed, 10 Jan 2024 05:25:46 GMT</pubDate> <guid>https://cds.cern.ch/record/2886006</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2886006/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Potential and constraints of a beam-beam wire compensator in the HL-LHC era</title> <link>https://cds.cern.ch/record/2883877</link> <description>The compensation of the long-range beam-beam interactions by DC wires is currently being investigated as an option for enhancing machine performance in the framework of the High-Luminosity LHC Project. In this paper, we report and comment on the potential of wire compensation during the first HL-LHC run. The results are based on numerical simulations and optimisations of the machine dynamic aperture varying the wire position and current, taking into account the latest optics and beam scenarios and the constraints imposed by the corresponding settings of the HL-LHC collimation system.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, G</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bertarelli, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Papaphilippou, Y</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Poyet, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Rossi, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bélanger, P</dc:creator> <pubDate>Wed, 13 Dec 2023 05:46:29 GMT</pubDate> <guid>https://cds.cern.ch/record/2883877</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2883877/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Impact of Crab Cavity RF noise on the transverse beam profiles in the HL-LHC</title> <link>https://cds.cern.ch/record/2883865</link> <description>Crab Cavities (CCs) are a key component for the HL-LHC luminosity upgrade. To significantly reduce the Long-Range Beam-Beam (LRBB) effects a large crossing angle scheme is needed . The installation of 4 CCs per beam in each of the two main interaction points aims to restore the luminosity loss caused by the crossing angle. Noise injected through the Low-Level RF (LLRF) system in these cavities is known to be affecting the growth of the transverse bunch emittance. In this paper a new numerical study has been developed thanks to the new tracking tool Xsuite to study in depth this detrimental effect of both phase and amplitude LLRF noise. Both Long Range and Head On Beam Beam effects are included in the simulation together with the CC noise to evaluate the effects of the interplay between these strong non-linearities and the external noise. Furthermore, transverse bunch measurements show that the transverse distribution can be modeled as an heavy tailed q-Gaussian. To take this into account a particular focus is given to the linear matching and subsequent tracking of a multivariate q-Gaussian distribution in the lattice. The Emittance Growth Rate induced on both a Gaussian and a q-Gaussian bunch is computed. This study could serve as a basis to evaluate the cross-talk between the two beams introduced by their head-on interaction in this heavy tailed scenario.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Fornara, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Appleby, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, G</dc:creator> <pubDate>Wed, 13 Dec 2023 05:46:19 GMT</pubDate> <guid>https://cds.cern.ch/record/2883865</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2883865/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Modelling the experimental data for long-range beam-beam wire compensators at the CERN LHC with diffusive models</title> <link>https://cds.cern.ch/record/2883858</link> <description>Current-carrying wires have long been proposed as measures to mitigate beam-beam effects. Dedicated hardware has been installed at CERN Large Hadron Collider (LHC) and experimental sessions have been organised to study the beam dynamics in the presence of the wire compensators. In this paper, a diffusive model is presented to model the collected experimental data and its performance is discussed in detail.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Montanari, C E</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bazzani, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Giovannozzi, M</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Poyet, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, G</dc:creator> <pubDate>Wed, 13 Dec 2023 05:46:15 GMT</pubDate> <guid>https://cds.cern.ch/record/2883858</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2883858/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Beam-beam long-range wire compensators in LHC Run 3</title> <link>https://cds.cern.ch/record/2883856</link> <description>Beam-beam effects are known to undermine the performance of the LHC during proton-proton collisions. In order to enhance the luminosity production and increase the tolerance of the working point of the machine after the High Luminosity upgrade of the LHC, it is relevant to study the possibility of using current-carrying wires to compensate long-range beam-beam effects. Following proof of principle studies in LHC Run 2, beam-beam wire compensators embedded in the collimators of the LHC are used in standard operation since the start of Run 3. In this paper, a figure of merit quantifying the efficiency of luminosity production is introduced and measurements from LHC Run 3 are presented. Bunch-by-bunch data is used to demonstrate the successful compensation of beam-beam effects in the LHC.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bélanger, P</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Baartman, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kaltchev, D</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, G</dc:creator> <pubDate>Wed, 13 Dec 2023 05:46:14 GMT</pubDate> <guid>https://cds.cern.ch/record/2883856</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2883856/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Dynamic aperture studies for the first run of High Luminosity LHC</title> <link>https://cds.cern.ch/record/2883815</link> <description>Dynamic Aperture (DA) studies based on single-particle tracking simulations have proven to be a powerful tool for optimizing the performance of the Large Hadron Collider (LHC), as well as its future High-Luminosity upgrade (HL-LHC). The present paper presents the studies performed for the first year of HL-LHC operation at the beginning of the fourth operational run of the LHC. The main focus lies on the exploration of new optics scenarios such as flat optics, where the transverse beam sizes at the high-luminosity interactions points are not equal. Multi-parametric DA studies and Frequency Map Analysis are deployed to derive the best parameters for operation for the start and end of the luminosity leveling with flat optics.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kostoglou, S</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bartosik, H</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">De Maria, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Iadarola, G</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, G</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Tomas Garcia, R</dc:creator> <pubDate>Wed, 13 Dec 2023 05:45:44 GMT</pubDate> <guid>https://cds.cern.ch/record/2883815</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2883815/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/"/> </item> <item> <title>Xsuite: an integrated beam physics simulation framework</title> <link>https://cds.cern.ch/record/2882300</link> <description>Xsuite is a newly developed modular simulation package combining in a single flexible and modern framework the capabilities of different tools developed at CERN in the past decades, notably Sixtrack, Sixtracklib, COMBI and PyHEADTAIL. The suite consists of a set of Python modules (Xobjects, Xpart, Xtrack, Xcoll, Xfields, Xdeps) that can be flexibly combined together and with other accelerator-specific and general-purpose python tools to study complex simulation scenarios. The code allows for symplectic modeling of the particle dynamics, combined with the effect of synchrotron radiation, impedances, feedbacks, space charge, electron cloud, beam-beam, beamstrahlung, and electron lenses. For collimation studies, beam-matter interaction is simulated using the K2 scattering model or interfacing Xsuite with the BDSIM/Geant4 library. Tools are available to compute the accelerator optics functions from the tracking model and to generate particle distributions matched to the optics. Different computing platforms are supported, including conventional CPUs, as well as GPUs from different vendors.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Iadarola, Giovanni</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Abramov, Andrey</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Belanger, Philippe</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Buffat, Xavier</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">De Maria, Riccardo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Demetriadou, Despina</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Deniau, Laurent</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Di Croce, Davide</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hermes, Pascal</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kicsiny, Peter</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kruyt, Peter</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Latina, Andrea</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Łopaciuk, Szymon</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mether, Lotta</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Niedermayer, Philipp</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Paraschou, Konstantinos</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Pieloni, Tatiana</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Seidel, Mike</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Van der Veken, Frederik</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">van Riesen-Haupt, Léon</dc:creator> <pubDate>Tue, 28 Nov 2023 03:16:06 GMT</pubDate> <dc:date xmlns:dc="http://purl.org/dc/elements/1.1/">2023-09-30</dc:date> <dc:source xmlns:dc="http://purl.org/dc/elements/1.1/">arXiv:2310.00317</dc:source> <guid>https://cds.cern.ch/record/2882300</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2882300/files/2310.00317.pdf"/> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2882300/files/document.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">['arXiv:2310.00317']</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/">arXiv:2310.00317</dc:hasVersion> </item> <item> <title>Machine Configuration for the 2023 Proton Run (MD7003)</title> <link>https://cds.cern.ch/record/2856778</link> <description>This note contains a condensed summary of the various beam tests which took place in 2022 in order to validate the machine configuration planned to be deployed for the 2023 proton run of the LHC, including in particular a combined ramp and anti-telescopic squeeze, the rotation of the external crossing angle in LHCb, and beam operation with up to 1.8 × 1011 p/b.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Fartoukh, Stephane</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Dilly, Joschua Werner</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hostettler, Michi</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Iadarola, Giovanni</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Jacquet, Delphine</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kostoglou, Sofia</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mirarchi, Daniele</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Persson, Tobias Hakan Bjorn</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Solfaroli Camillocci, Matteo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sterbini, Guido</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Soubelet, Felix</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Tomas Garcia, Rogelio</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Trad, Georges</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Van Der Veken, Frederik</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Wenninger, Jorg</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">CERN. Geneva. ATS Department</dc:creator> <pubDate>Mon, 24 Apr 2023 10:04:54 GMT</pubDate> <dc:date xmlns:dc="http://purl.org/dc/elements/1.1/">01 Mar 2023</dc:date> <dc:source xmlns:dc="http://purl.org/dc/elements/1.1/">CERN-ACC-NOTE-2023-0005</dc:source> <guid>https://cds.cern.ch/record/2856778</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2856778/files/CERN-ACC-NOTE-2023-0005.pdf"/> <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="fr"/> <dc:hasPart xmlns:dc="http://purl.org/dc/elements/1.1/">2023</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/">0005</dc:hasVersion> </item> </channel> </rss>