<?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 13:57:32 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=Baudrenghien%2C+Philippe" /> <atom:link rel="self" href="/rss?f=author&amp;ln=pl&amp;p=Baudrenghien%2C+Philippe" /> <opensearch:totalResults>59</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>Mitigation Strategies for the Instabilities Induced by the Fundamental Mode of the HL-LHC Crab Cavities</title> <link>https://cds.cern.ch/record/2918206</link> <description>The transverse impedance is one of the potentially limiting effects for the performance of the High-Luminosity Large Hadron Collider (HL-LHC). In the current LHC, the impedance is dominated by the resistive-wall contribution of the collimators at typical bunch-spectrum frequencies, and is of broad-band nature. Nevertheless, the fundamental mode of the crab cavities, that are a vital part of the HL-LHC baseline, adds a strong and narrow-band contribution. The resulting coupled-bunch instability, which contains a strong head-tail component, requires dedicated mitigation measures, since the efficiency of the transverse damper is limited against such instabilities, and Landau damping from octupoles would not be sufficient. The efficiency and implications of various mitigation strategies, based on RF feedbacks and optics changes, are discussed, along with first measurements using crab cavity prototypes at the Super Proton Synchrotron (SPS).</description> <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/">Baudrenghien, 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/">Calaga, Rama</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mounet, Nicolas</dc:creator> <pubDate>Thu, 28 Nov 2024 05:06:59 GMT</pubDate> <guid>https://cds.cern.ch/record/2918206</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2918206/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>Performance of the Ion Chain at the CERN Injector Complex and Transmission Studies During the 2023 Slip Stacking Commissioning</title> <link>https://cds.cern.ch/record/2901240</link> <description>The 2023 run has been decisive for the LHC Ion Injector Complex. It demonstrated the capability of producing full trains of momentum slip stacked lead ions in the SPS. Slip stacking is a technique of interleaving particle trains, reducing the bunch spacing in SPS from 100 ns to 50 ns. It is needed to reach the total ion intensity requested by the HL-LHC project, as defined by updated common LIU/HL-LHC target beam parameters. This paper reviews the lead beam characteristics across the Ion Injector Complex, including transmission efficiencies up to the SPS extraction. It also documents the difficulties found during the commissioning and the solutions put in place.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Slupecki, Maciej</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/">Alemany-Fernández, Reyes</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Angoletta, Maria Elena</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Argyropoulos, Theodoros</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/">Baudrenghien, Philippe</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bellodi, Giulia</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bozzolan, Michele</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bruce, Roderik</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Carli, Christian</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Cenede, Jean</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Damerau, Heiko</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Frassier, Alexandre</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Gamba, Davide</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hagman, Gregoire</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Huschauer, Alexander</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kain, Verena</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Khatri, Ghanshyambhai</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Küchler, Detlef</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lasheen, Alexandre</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Li, Kevin</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mahner, Edgar</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Papotti, Giulia</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Piccinini, Giampaolo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Rey, Anthony</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Schenk, Michael</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Scrivens, Richard</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Spierer, Arthur</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Tranquille, Gerard</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/">Velotti, Francesco</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Waagaard, Elias</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Wegner, Rolf</dc:creator> <pubDate>Tue, 18 Jun 2024 05:49:10 GMT</pubDate> <guid>https://cds.cern.ch/record/2901240</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2901240/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 Performance with the LHC Injectors Upgrade</title> <link>https://cds.cern.ch/record/2900871</link> <description>The LHC Injectors Upgrade (LIU) project was put in place between 2010 and 2021 to increase the intensity and brightness in the LHC injectors to match the challenging requirements of the High-Luminosity LHC (HL-LHC) project, while ensuring reliable operation of the injectors complex up to the end of the HL-LHC era (ca. 2040). During the 2019-2020 CERN accelerators shutdown, extensive hardware modifications were implemented in the entire LHC proton and ion injection chains, involving the new Linac4, the Proton Synchrotron Booster (PSB), the Proton Synchrotron (PS), the Super Proton Synchrotron (SPS) and the ion PS injectors, i.e. the Linac3 and the Low Energy Ion Ring (LEIR). Since 2021, beams have been recommissioned throughout the injectors’ chain and the beam parameters are being gradually ramped up to meet the LIU specifications using new beam dynamics solutions adapted to the upgraded accelerators. This paper focuses on the proton beams and describes the current state of the art.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">zannini, C</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Wegner, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Vollinger, C</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Veness, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Velotti, F</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sullivan, M</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Steerenberg, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Spierer, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Skowronski, P</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sito, L</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Shaposhnikova, E</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Scrivens, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Schenk, M</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/">Roncarolo, F</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Quartullo, D</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Prodon, S</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Prebibaj, T</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Pedrosa, F</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Pasquino, C</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/">Papotti, G</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/">Montesinos, E</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mikulec, 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/">Meddahi, M</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mases Sole, I</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Manglunki, D</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Maclean, E</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lombardi, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Li, K</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Levens, T</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lasheen, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lallement, J -B</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Karpov, I</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kain, V</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/">Huschauer, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hanke, K</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hagmann, G</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Goddard, B</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Gildardoni, S</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Garoby, R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Funken, A</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">De la Fuente Garcia, E</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Rumolo, Giovanni</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/">Alemany-Fernández, Reyes</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Angoletta, Maria Elena</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Antuono, Chiara</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Argyropoulos, Theodoros</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/">Barnes, Michael</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/">Baudrenghien, Philippe</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bellodi, Giulia</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Biancacci, Nicolo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bracco, Chiara</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bruchon, Niky</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Carlier, Etienne</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Coupard, Julie</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Damerau, Heiko</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Di Giovanni, Gian Piero</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Findlay, Alan</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Fraser, Matthew</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Funken, Anne</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Garoby, Roland</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Gilardoni, Simone</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Goddard, Brennan</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hagmann, Gregoire</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hanke, Klaus</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Huschauer, Alexander</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/">Kain, Verena</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Karpov, Ivan</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lallement, Jean-Baptiste</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lasheen, Alexandre</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/">Li, Kevin</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lombardi, Alessandra</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Maclean, Ewen</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Manglunki, Django</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mases Solé, Ingrid</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Meddahi, Malika</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/">Mikulec, Bettina</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Montesinos, Eric</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Papaphilippou, Yannis</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Papotti, Giulia</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/">Pasquino, Chiara</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Pedrosa, Fernando</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/">Prodon, Sylvie</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Quartullo, Danilo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Roncarolo, Federico</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Salvant, Benoit</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Schenk, Michael</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Scrivens, Richard</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Shaposhnikova, Elena</dc:creator> <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/">Skowroński, Piotr</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Spierer, Arthur</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Steerenberg, Rende</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sullivan, Michael</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Velotti, Francesco</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Veness, Raymond</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Vollinger, Christine</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Wegner, Rolf</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Zannini, Carlo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">de la Fuente, Elena</dc:creator> <pubDate>Sat, 15 Jun 2024 04:02:28 GMT</pubDate> <guid>https://cds.cern.ch/record/2900871</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2900871/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>HL-LHC Crab Cavity Field Regulation and Resulting RF Noise Spectrum</title> <link>https://cds.cern.ch/record/2859258</link> <description>The HL-LHC Low Level RF (LLRF) must fulfill three requirements: it must reduce the cavity impedance at the fundamental below the instability threshold, it must regulate the crab cavity voltage precisely (amplitude and phase), and it must provide a cavity field with a spectral purity resulting in negligible degradation of the integrated luminosity due to transverse emittance growth. In this note, we present a LLRF system that fulfills these objectives. We then provide an estimate of the crab cavity RF noise spectrum for this LLRF system, a key parameter to evaluate transverse emittance growth.</description> <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/">Mastoridis, Themistoklis</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">CERN. Geneva. ATS Department</dc:creator> <pubDate>Fri, 19 May 2023 09:06:00 GMT</pubDate> <dc:date xmlns:dc="http://purl.org/dc/elements/1.1/">19 May 2023</dc:date> <dc:source xmlns:dc="http://purl.org/dc/elements/1.1/">CERN-ACC-NOTE-2023-0006</dc:source> <guid>https://cds.cern.ch/record/2859258</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2859258/files/CCnoiseNoteFinal.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/">0006</dc:hasVersion> </item> <item> <title>Suppression of Crab Cavity Noise Induced Emittance Growth by Transverse Beam Coupling Impedance</title> <link>https://cds.cern.ch/record/2845897</link> <description>Crab cavities are a key component of the High Luminosity LHC (HL-LHC) upgrade, as they aim to mitigate the luminosity reduction induced by the crossing angle. Two superconducting crab cavities (CCs) were installed in the Super Proton Synchrotron (SPS) at CERN in 2018 to demonstrate their operation in a proton machine for the first time. An important point to consider is the transverse emittance growth induced by noise in the CC RF system. During a first experimental campaign in 2018, the measured emittance growth was found to be a factor of 4 lower than predicted by analytical models. In this paper, the effects of transverse beam coupling impedance on emittance growth driven by CC RF noise are presented and the results of the second experimental campaign, which took place in the SPS in 2022, are discussed.</description> <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/">Antoniou, Fanouria</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/">Baudrenghien, 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/">Calaga, Rama</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mastoridis, Themis</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Papaphilippou, Yannis</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Wolski, Andrzej</dc:creator> <pubDate>Wed, 11 Jan 2023 05:09:54 GMT</pubDate> <guid>https://cds.cern.ch/record/2845897</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2845897/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>The CERN SPS Low level RF: The Cavity-Controller</title> <link>https://cds.cern.ch/record/2845887</link> <description>This paper is the second of a series of three on the Super Proton Synchrotron (SPS) Low Level RF (LLRF) upgrade. It covers the 200MHz Cavity-Controller part, that is responsible for the regulation of the accelerating field in a single SPS cavity. When the SPS is used as Large Hadron Collider (LHC) proton injector, the issue is the high beam loading that must be compensated to guarantee longitudinal stability and constant parameters over the bunch train. That calls for strong One-Turn Delay Feedback (OTFB) and Feed-Forward (FFWD). The SPS is also accelerating Lead ions (Pb). There the issue is Frequency-Modulation (FM) and Amplitude-Modulation (AM) over the turn (so called Fixed Frequency Acceleration - FFA) plus RF gymnastics for the new ions slip-stacking. The paper reviews the functional requirements, presents the block diagram, then gives details on the signal processing, firmware and hardware. Finally results from the first year of beam commissioning are presented (2021).</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hagmann, Gregoire</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/">Egli, Julien</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Spierer, Arthur</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sumiński, Maciej</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Włostowski, Tomasz</dc:creator> <pubDate>Wed, 11 Jan 2023 05:09:47 GMT</pubDate> <guid>https://cds.cern.ch/record/2845887</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2845887/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>The CERN SPS Low Level RF: Lead Ions Acceleration</title> <link>https://cds.cern.ch/record/2845800</link> <description>This paper is the third of a series of three on the Super Proton Synchrotron (SPS) Low Level RF (LLRF). Its focus is the upgrade concerned with the acceleration of Lead ions for injection into the LHC. Lead ions are far from relativistic at injection into the SPS. Therefore, the classic acceleration scheme at constant harmonic number (h=4620) does not work as the RF frequency swing does not fit within the cavity bandwidth. Fixed Frequency Acceleration (FFA) is therefore used. The upgraded LLRF uses a completely new implementation of the FFA, based on a Numerically Controlled Oscillator (NCO) implemented as an FPGA IP in the Controller of each cavity. In addition, the 2022 scheme for LHC ions filling calls for slip-stacking of two families of bunches, 100 ns spacing, to generate a 50 ns spacing after interleaving. The paper presents the key components for FFA and ions slip-stacking as implemented in the new system, together with successful first tests performed in Autumn 2021</description> <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/">Egli, Julien</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hagmann, Gregoire</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Spierer, Arthur</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Włostowski, Tomasz</dc:creator> <pubDate>Wed, 11 Jan 2023 05:08:44 GMT</pubDate> <guid>https://cds.cern.ch/record/2845800</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2845800/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>The CERN SPS Low Level RF: The Beam-Control</title> <link>https://cds.cern.ch/record/2845762</link> <description>The Super Proton Synchrotron (SPS) Low Level RF (LLRF) has been completely upgraded during the CERN long shutdown (LS2, 2019-2020). The old NIM and VME based, mainly analog system has been replaced with modern digital electronics implemented on a MicroTCA platform. The architecture has also been reviewed, with synchronization between RF stations now resting on the White Rabbit (WR) deterministic link. This paper is the first of a series of three on the SPS LLRF upgrade. It covers the Beam-Control part, that is responsible for the generation of the RF reference frequency from a measurement of the magnetic field, and beam phase and radial position. It broadcasts this frequency word to the RF stations, via a White Rabbit network. The paper presents the architecture, gives details on the signal processing, firmware, hardware and software. Finally, results from the first year of beam commissioning are presented (2021).</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Spierer, Arthur</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/">Egli, Julien</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hagmann, Gregoire</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kuzmanović, Predrag</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Stachon, Ireneusz</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sumiński, Maciej</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Włostowski, Tomasz</dc:creator> <pubDate>Wed, 11 Jan 2023 05:08:15 GMT</pubDate> <guid>https://cds.cern.ch/record/2845762</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2845762/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>Achievements and Performance Prospects of the Upgraded LHC Injectors</title> <link>https://cds.cern.ch/record/2845730</link> <description>To provide HL-LHC performance, the CERN LHC injector chain underwent a major upgrade during an almost 2-year-long shutdown. In the first half of 2021 the injectors were gradually re-started with the aim to reach at least pre-shutdown parameters for LHC as well as for fixed target beams. The strategy of the commissioning across the complex, a summary of the many challenges and finally the achievements will be presented. Several lessons were learned and have been integrated to define the strategy for the performance ramp-up over the coming years. Remaining limitations and prospects for LHC beam parameters at the exit of the LHC injector chain in the years to come will be discussed. Finally, the emerging need for improved operability of the CERN complex will be addressed, with a description of the first efforts to meet the availability and flexibility requirements of the HL-LHC era while at the same time maximizing fixed target physics output.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kain, Verena</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/">Alemany-Fernández, Reyes</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Angoletta, Maria Elena</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Antoniou, Fanouria</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Argyropoulos, Theodoros</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/">Balhan, Bruno</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Barnes, Michael</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Barrientos, Diego</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/">Baudrenghien, Philippe</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bellodi, Giulia</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Biancacci, Nicolo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Boccardi, Andrea</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Borburgh, Jan</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bracco, Chiara</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Carlier, Etienne</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Cotte, Denis</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Coupard, Julie</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Damerau, Heiko</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Di Giovanni, Gian Piero</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Findlay, Alan</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Fraser, Matthew</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Funken, Anne</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Goddard, Brennan</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hagmann, Gregoire</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hanke, Klaus</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Huschauer, Alexander</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Jaussi, Michael</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Karpov, Ivan</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Koevener, Toke</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Küchler, Detlef</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lallement, Jean-Baptiste</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lasheen, Alexandre</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/">Li, Kevin</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lombardi, Alessandra</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Madysa, Nico</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mahner, Edgar</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Meddahi, Malika</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/">Mikulec, Bettina</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Molendijk, John</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Montesinos, Eric</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Nisbet, David</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Nuiry, Francois-Xavier</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Papotti, Giulia</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/">Pedrosa, Fernando</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/">Prodon, Sylvie</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Quartullo, Danilo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Renner, Elisabeth</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Roncarolo, Federico</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Rumolo, Giovanni</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Salvant, Benoit</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Schenk, Michael</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Scrivens, Richard</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Shaposhnikova, Elena</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Skowroński, Piotr</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Spierer, Arthur</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Tecker, Frank</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/">Velotti, Francesco</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Wegner, Rolf</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Zannini, Carlo</dc:creator> <pubDate>Wed, 11 Jan 2023 05:07:50 GMT</pubDate> <guid>https://cds.cern.ch/record/2845730</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2845730/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>Low Level RF Control Algorithms for the CERN Proton LINAC4</title> <link>https://cds.cern.ch/record/2844859</link> <description>The CERN Linac4 Low Level RF (LLRF) uses a Linear Quadratic Gaussian regulator and an Adaptive Feed Forward to stabilize the accelerating field in the cavities in the presence of strong beam loading. A Klystron Polar Loop is also implemented to compensate the RF perturbations caused by the ripples and droop in the klystron High Voltage supply. The paper presents the important parts of the regulation, shows results as the system has evolved from first prototype (2013) to operational beams (2020), and mentions some important issues encountered during the commissioning and the first years of operation, with their mitigations.</description> <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/">Bielawski, Bartosz Przemyslaw</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Borner, Robert</dc:creator> <pubDate>Sun, 18 Dec 2022 05:01:36 GMT</pubDate> <guid>https://cds.cern.ch/record/2844859</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2844859/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>Operational Scenario of First High Luminosity LHC Run</title> <link>https://cds.cern.ch/record/2839976</link> <description>A new scenario for the first operational run of the HL-LHC era (Run 4) has been recently developed to accommodate a period of performance ramp-up to achieve an annual integrated luminosity close to the nominal HL-LHC design. The operational scenario in terms of beam parameters and machine settings, as well as the different phases, are described here along with the impact of potential delays on key hardware components.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Tomás García, Rogelio</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Arduini, Gianluigi</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/">Bruce, Roderik</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Brüning, Oliver</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/">Calaga, Rama</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Cerutti, Francesco</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/">Dilly, Joschua</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/">Giovannozzi, Massimo</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/">Iadarola, Giovanni</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Jones, Owain Rhodri</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/">Lindström, B</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Maclean, Ewen</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/">Métral, Elias</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Papaphilippou, Yannis</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Persson, T H B</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Pugnat, T</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Redaelli, Stefano</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/">Timko, Helga</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/">Zerlauth, Markus</dc:creator> <pubDate>Wed, 09 Nov 2022 07:30:03 GMT</pubDate> <guid>https://cds.cern.ch/record/2839976</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2839976/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>Investigation of Damping Effects of the Crab Cavity Noise Induced Emittance Growth</title> <link>https://cds.cern.ch/record/2811864</link> <description>Crab cavities will be installed at the two main interaction points (IP1 and IP5) of the High Luminosity LHC (HL-LHC) in order to minimize the geometric reduction of the luminosity due to the crossing angle. Two prototype crab cavities have been installed into the SPS machine and were tested with a proton beam in 2018, to study the expected emittance growth induced by RF noise. The measured emittance growth was found to be a factor 2-3 lower than predicted from the available analytical and computational models. Damping mechanisms from the transverse impedance, which is not included in the available theories, are studied as a possible explanation for the observed discrepancy.</description> <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/">Antoniou, Fanouria</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/">Baudrenghien, 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/">Calaga, Rama</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Carver, Lee R</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Mastoridis, Themis</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Papaphilippou, Yannis</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Wolski, Andrzej</dc:creator> <pubDate>Fri, 10 Jun 2022 04:44:46 GMT</pubDate> <guid>https://cds.cern.ch/record/2811864</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2811864/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>Cavity Control Modelling for SPS-to-LHC Beam Transfer Studies</title> <link>https://cds.cern.ch/record/2811417</link> <description>To accurately simulate injection losses in the LHC and the High-Luminosity LHC era, a realistic beam distribution model at SPS extraction is needed. To achieve this, the beam-loading compensation by the SPS cavity controller has to be included, as it modulates the bunch positions with respect to the rf buckets. This dynamic cavity control model also allows generating a more realistic beam halo, from which the LHC injection losses will mainly originate. In this paper, the implementation of the present SPS cavity controller in CERN’s Beam Longitudinal Dynamics particle tracking code is described. Just like in the machine, the feedback and feedforward controls are included in the simulation model, as well as the generator-beam-cavity interaction. Benchmarking against measurements of the generated beam distributions at SPS extraction are presented.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Medina Medrano, Luis</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Argyropoulos, Theodoros</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/">Timko, Helga</dc:creator> <pubDate>Sat, 04 Jun 2022 04:06:21 GMT</pubDate> <guid>https://cds.cern.ch/record/2811417</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2811417/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>White Rabbit and MTCA.4 Use in the LLRF Upgrade for CERN’s SPS</title> <link>https://cds.cern.ch/record/2809576</link> <description>The Super Proton Synchrotron (SPS) Low-level RF (LLRF) system at CERN was completely revamped in 2020. In the old system, the digital signal processing was clocked by a submultiple of the RF. The new system uses a fixed-frequency clock derived from White Rabbit (WR). This triggered the development of an eRTM module for generating very precise clock signals to be fed to the optional RF backplane in MTCA.4 crates. The eRTM14/15 sandwich of modules implements a WR node delivering clock signals with a jitter below 100 fs. WR-clocked RF synthesis inside the FPGA makes it simple to reproduce the RF elsewhere by broadcasting the frequency-tuning words over the WR network itself. These words are received by the WR2RF-VME module and used to produce beam-synchronous signals such as the bunch clock and the revolution tick. This paper explains the general architecture of this new LLRF system, highlighting the role of WR-based synchronization. It then goes on to describe the hardware and gateware designs for both modules, along with their supporting software. A recount of our experience with the deployment of the MTCA.4 platform is also provided.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Włostowski, Tomasz</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Adrianek, Karol</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Arruat, Michel</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/">Butterworth, Andrew</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Daniluk, Grzegorz</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Egli, Julien</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Gill, John</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Gingold, Tristan</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">González Cobas, Juan</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hagmann, Gregoire</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kuzmanović, Predrag</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lampridis, Dimitrios</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lipiński, Maciej</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Novel González, Saul</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Palluel, Julien</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Rizzi, Mattia</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Spierer, Arthur</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Sumiński, Maciej</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Wujek, Adam</dc:creator> <pubDate>Mon, 16 May 2022 15:11:25 GMT</pubDate> <guid>https://cds.cern.ch/record/2809576</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2809576/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>HL-LHC Run 4 proton operational scenario</title> <link>https://cds.cern.ch/record/2803611</link> <description>Following new findings in beam dynamics and the latest HL-LHC project decisions, an operational scenario has been developed for the first HL-LHC run, Run 4. This new scenario is presented in this document along with the motivations for the proposed changes and performance estimates.</description> <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/">Arduini, Gianluigi</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/">Bruning, Oliver</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Bruce, Roderik</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/">Calaga, Rama</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/">Dilly, Joschua Werner</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/">Giovannozzi, Massimo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hermes, Pascal Dominik</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/">Kostoglou, Sofia</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Lindstrom, Bjorn Hans Filip</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Maclean, Ewen Hamish</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Metral, Elias</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/">Papaphilippou, Yannis</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/">Pugnat, Thomas</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Redaelli, Stefano</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/">Timko, Helga</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/">Zerlauth, Markus</dc:creator> <pubDate>Fri, 11 Mar 2022 09:47:22 GMT</pubDate> <dc:date xmlns:dc="http://purl.org/dc/elements/1.1/">29 Jun 2022</dc:date> <dc:source xmlns:dc="http://purl.org/dc/elements/1.1/">CERN-ACC-2022-0001</dc:source> <guid>https://cds.cern.ch/record/2803611</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2803611/files/CERN-ACC-2022-0001.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/">2022</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/">0001</dc:hasVersion> </item> <item> <title>A new beam synchronous processing architecture with a fixed frequency processing clock. Application to transient beam loading compensation in the CERN SPS machine</title> <link>https://cds.cern.ch/record/2747959</link> <description>New projects being implemented or planned at CERN, such as the LHC Injectors Upgrade (LIU), the High-Luminosity LHC (HL-LHC) or the Future Circular Collider (FCC), motivate the change of several architectural paradigms in the Low Level RF systems (LLRF). In the upgraded Super Proton Synchrotron (SPS) LLRF, the distribution of RF, the revolution frequency, settings and synchronization timings will rely on a deterministic link, the White Rabbit (WR), exploiting a distributed topology. The digital electronics (FPGA) will now use a fixed frequency clock extracted locally in each node from this data stream. The paper presents a new solution for algorithms that treat beam-induced perturbations as they must solve the challenge to tune their processing to the instantaneous revolution frequency, Beam Synchronous Processing (BSP). We use dynamic resampling of uniform sampled data as tuning element between a sweeping spectrum and the static processing implemented with fixed frequency clocks. The paper applies the novel Beam Synchronous Processing method to transient beam loading compensation. It presents a One Turn delay FeedBack (OTFB) for the SPS based on a cascade of two variable ratio resamplers.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Galindo Guarch, F Javier</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/">Moreno Arostegui, J Manuel</dc:creator> <pubDate>Thu, 17 Dec 2020 05:00:58 GMT</pubDate> <guid>https://cds.cern.ch/record/2747959</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2747959/files/1-s2.0-S0168900220312912-main.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>An Architecture for Real-Time Arbitrary and Variable Sampling Rate Conversion With Application to the Processing of Harmonic Signals</title> <link>https://cds.cern.ch/record/2724301</link> <description>The paper presents a new solution for sampling rate conversion and processing of harmonic signals with known but possibly varying fundamental frequency. This problem is commonly found in particle accelerators, for tracking the beam signals whose revolution frequency varies during the acceleration ramp. It is also common among many other fields such as speech and music processing, removal of mechanical noises, filtering of biomedical recordings, active crack imaging, etc. The key element in the proposed solution is a new architecture for a Farrow-based resampler, in which the resampling ratio can take any value and can be modified continuously to follow the signal fundamental frequency. The combination of two complementary resamplers creates a processing region where signal synchronous processing is performed. The resampler architecture is optimized for modern FPGA features. It decouples the processing and sampling clocks, and uses a single processing (hardware) clock whose frequency remains fixed. The functional model was migrated to Xilinx System Generator and the overall performance is evaluated with an application that filters a periodic signal whose frequency follows a known linear ramp in the presence of additive white noise.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Guarch, Fco Javier Galindo</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/">Moreno Arostegui, Juan Manuel</dc:creator> <pubDate>Mon, 20 Jul 2020 09:42:34 GMT</pubDate> <guid>https://cds.cern.ch/record/2724301</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2724301/files/08949759.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>I/Q Model of the SPS 200 MHz Travelling Wave Cavity and Feedforward Design</title> <link>https://cds.cern.ch/record/2719232</link> <description>As part of the LHC injector upgrade project (LIU), that calls for the doubling of the bunch intensity injected from the SPS into the LHC, the SPS Low Level RF (LLRF) is fully upgraded during the LHC Long-Shutdown 2 (LS2). A major issue is the compensation of the beam induced voltage (beam loading) in the 200 MHz Travelling Wave Cavities (TWCs). Uncompensated beam loading limits the intensity threshold above which longitudinal coupled bunch instabilities develop. The SPS beam consists of batches separated by gaps. Given the short cavity filling time, this results in a large transient of beam induced voltage along the batch, with resulting bunch-to-bunch variation of voltage and phase. The phase variation along the batch is a major concern for the alignment of the harmonic cavities used for Landau damping (800 MHz). The LLRF uses two systems for beam loading compensation: The One-Turn delay Feedback (OTFB) and the Feedforward. Both are implemented in I/Q coordinates. These systems are being developed now, for a restart of the SPS in early 2021. This Note derives equations for the I/Q representation of the Generator-Cavity-Beam interaction (TWC case) and then uses this formalism for the design of an optimal Feedforward system. </description> <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/">Mastoridis, Themistoklis</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">CERN. Geneva. ATS Department</dc:creator> <pubDate>Thu, 28 May 2020 14:03:34 GMT</pubDate> <dc:date xmlns:dc="http://purl.org/dc/elements/1.1/">25 May 2020</dc:date> <dc:source xmlns:dc="http://purl.org/dc/elements/1.1/">CERN-ACC-NOTE-2020-0032</dc:source> <guid>https://cds.cern.ch/record/2719232</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2719232/files/IQ Model of the SPS 200 MHz Travelling Wave Cavity and Feedforward Design.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/">2020</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/">0032</dc:hasVersion> </item> <item> <title>Operation Experience with the LHC ACS RF System</title> <link>https://cds.cern.ch/record/2712616</link> <description>The LHC accelerating RF system consists of two cryomodules per beam, each containing four single-cell niobium sputtered 400.8 MHz superconducting cavities working at 4.5 K and an average accelerating voltage of 2 MV. The paper summarises the experience, availability and evolution of the system within 10 years of operation. The lessons learned from the successful replacement and re-commissioning of one cryomodule with a spare module, and the recent re-test of the originally installed module on the test stand are also included. Finally, a review of currently launched spare cavity production and long-term developments are presented.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Turaj, Katarzyna</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Arnaudon, Luca</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/">Brunner, Olivier</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Butterworth, Andrew</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Gerigk, Frank</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Karppinen, Mikko</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Maesen, Pierre</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Montesinos, Eric</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Peauger, Franck</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Rosaz, Guillaume</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Shaposhnikova, Elena</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Smekens, David</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Taborelli, Mauro</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Therasse, Mathieu</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Timko, Helga</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/">Valverde Alonso, Nuria</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Venturini Delsolaro, Walter</dc:creator> <pubDate>Tue, 10 Mar 2020 08:08:07 GMT</pubDate> <guid>https://cds.cern.ch/record/2712616</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2712616/files/10.18429_JACoW-SRF2019-THP031.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 loading compensation for the Future Circular hadron-hadron Collider (FCC-hh)</title> <link>https://cds.cern.ch/record/2696104</link> <description>The power consumption of the rf system can be minimised by optimising the cavity detuning and the loaded quality factor. In high-current accelerators, the presence of gaps in the filling results in a modulation of the cavity voltage along the ring (transient beam loading) and as a consequence a spread in the bunch parameters. In addition longitudinal coupled-bunch instabilities can appear, caused by the cavity impedance at the fundamental. Both issues can be mitigated by using an rf feedback around the amplifier and cavity, a technique used in many high intensity machines including the Large Hadron Collider (LHC). Compared to the LHC machine, the energy increase and the radiation loss for the Future Circular hadron-hadron Collider (FCC-hh) will be larger, resulting in a synchronous phase deviating significantly from 180 degrees. The solutions adopted for the LHC must therefore be revisited. This paper evaluates several beam loading compensation schemes for this machine.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Karpov, Ivan</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Baudrenghien, Philippe</dc:creator> <pubDate>Thu, 24 Oct 2019 04:43:38 GMT</pubDate> <guid>https://cds.cern.ch/record/2696104</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2696104/files/mopgw084.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>The CERN SPS Low Level RF upgrade project</title> <link>https://cds.cern.ch/record/2692799</link> <description>The High Luminosity LHC project (HL-LHC) calls for the doubling of the beam intensity injected from the Super Proton Synchrotron (SPS). This is not possible with the present RF system consisting of four 200 MHz cavities. An upgrade was therefore launched, consisting of the installation of two more cavities during the machine shutdown in 2019-2020 (LS2). Installation of more cavities requires the installation of extra Low Level RF (LLRF) electronics. The present LLRF system consists of the original equipment installed in the 1970s, plus some additions dating from the late 1990s when the SPS was commissioned as LHC injector. The High-Power RF upgrade has motivated a complete renovation of the LLRF during LS2; use of a MicroTCA platform, use of a digital deterministic link for synchronization (the so-called White Rabbit), use of an absolute clock for the processing, new algorithms for reducing the cavity impedance, and a complete re-design of the beam control loops and slip-stacking.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Hagmann, Gregoire</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/">Betz, Jochen</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Egli, Julien</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Galindo Guarch, Francisco Javier</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Kotzian, Gerd</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Rizzi, Mattia</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Schmid, Lorenz</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Spierer, Arthur</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Włostowski, Tomasz</dc:creator> <pubDate>Wed, 09 Oct 2019 04:01:04 GMT</pubDate> <guid>https://cds.cern.ch/record/2692799</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2692799/files/thprb082.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>Transient beam loading and rf power evaluation for future circular colliders</title> <link>https://cds.cern.ch/record/2688503</link> <description>Interaction of the beam with the fundamental impedance of the accelerating cavities can limit the performance of high-current accelerators. It can result in a significant variation of bunch-by-bunch parameters (bunch length, synchronous phase, etc.) if filling patterns contain gaps that are not negligible compared with the cavity filling time. In the present work, this limitation is analyzed using the steady-state time-domain approach for the high-current option (Z) of the future circular electron-positron collider and for the future circular hadron-hadron collider. Mitigation of transient beam loading by direct rf feedback is addressed with evaluation of additional required generator power.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Karpov, Ivan</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Baudrenghien, Philippe</dc:creator> <pubDate>Thu, 05 Sep 2019 04:35:53 GMT</pubDate> <guid>https://cds.cern.ch/record/2688503</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2688503/files/Fulltext from publisher.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 MD 3165: RF power limitations at flat bottom</title> <link>https://cds.cern.ch/record/2683350</link> <description>This note describes the power measurements at flat bottom with the half-detuning beam-loading scheme in the LHC performed with the aim to provide the basis for the extrapolation of the present RF power margins for Run 3 and the High-Luminosity LHC (HL-LHC). Due to the unavailability of HL-LHC beam currents for testing in the present LHC, as well as to the large error bars on power measurements, the maximum RF power available is estimated by determining the maximum RF voltage that can be maintained under several scenarios.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Medina Medrano, Luis Eduardo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Argyropoulos, Theodoros</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/">Brunner, Olivier</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/">Karpov, Ivan</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Peauger, Franck</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Shaposhnikova, Elena</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Timko, Helga</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Turaj, Katarzyna</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">CERN. Geneva. ATS Department</dc:creator> <pubDate>Fri, 19 Jul 2019 11:59:34 GMT</pubDate> <dc:date xmlns:dc="http://purl.org/dc/elements/1.1/">19 Jul 2019</dc:date> <dc:source xmlns:dc="http://purl.org/dc/elements/1.1/">CERN-ACC-NOTE-2019-0030</dc:source> <guid>https://cds.cern.ch/record/2683350</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2683350/files/LHC_MD_3165.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/">2019</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/">0030</dc:hasVersion> </item> <item> <title>LHC MDs 3163, 3164, and 3166: Injection oscillations throughout the cycle</title> <link>https://cds.cern.ch/record/2678029</link> <description>This note summarizes three inter-related machine development sessions that were performed in the LHC in the course of 2018. Long-lasting injection oscillations and beam stability at injection were investigated as a function of capture voltage in the MD 3164 on optimal injection voltage. The convergence of bunch lengths during the controlled emittance blow-up applied in the acceleration ramp was studied in the MD 3163. Finally, the bunch distribution at arrival to flat top was observed using peak-detected Schottky spectra in the MD 3166.</description> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Timko, Helga</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Argyropoulos, Theodoros</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/">Karpov, Ivan</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Medina Medrano, Luis Eduardo</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Peauger, Franck</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Shaposhnikova, Elena</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Turaj, Katarzyna</dc:creator> <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">CERN. Geneva. ATS Department</dc:creator> <pubDate>Tue, 11 Jun 2019 14:46:21 GMT</pubDate> <dc:date xmlns:dc="http://purl.org/dc/elements/1.1/">11 Jun 2019</dc:date> <dc:source xmlns:dc="http://purl.org/dc/elements/1.1/">CERN-ACC-NOTE-2019-0021</dc:source> <guid>https://cds.cern.ch/record/2678029</guid> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2678029/files/CERN-ACC-NOTE-2019-0021.pdf"/> <media:content xmlns:media="http://search.yahoo.com/mrss/" url="https://cds.cern.ch/record/2678029/files/CERN-ACC-NOTE-2019-0021.pdf?subformat=pdfa"/> <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/">2019</dc:hasPart> <dc:hasVersion xmlns:dc="http://purl.org/dc/elements/1.1/">0021</dc:hasVersion> </item> </channel> </rss>