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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">     <html xmlns="http://www.w3.org/1999/xhtml" lang="zh" xml:lang="zh" xmlns:og="http://ogp.me/ns#" xmlns:fb="http://ogp.me/ns/fb#"> <head> <title>Resonant and random excitations on the proton beam in the Large Hadron Collider for active halo control with pulsed hollow electron lenses - CERN Document Server</title> <link href='https://framework.web.cern.ch/framework/2.0/fonts/PTSansWeb/PTSansWeb.css' rel='stylesheet' type='text/css' /> <link rel="stylesheet" href="https://cds.cern.ch/img/invenio.css?v=20141127" type="text/css" /> <link rel="stylesheet" href="https://cds.cern.ch/img/cern_theme/css/cern_theme.css?v=20141127" type="text/css" /> <link rel="stylesheet"href="/css/font-awesome.min.css"> <meta http-equiv="X-UA-Compatible" content="IE=Edge"/> <link rel="stylesheet" href="https://cds.cern.ch/img/cern_toolbar/css/toolbar.css" type="text/css" />    <link rel="canonical" href="https://cds.cern.ch/record/2318948" /> <link rel="alternate" hreflang="el" href="https://cds.cern.ch/record/2318948?ln=el" /> <link rel="alternate" hreflang="fr" href="https://cds.cern.ch/record/2318948?ln=fr" /> <link rel="alternate" hreflang="bg" href="https://cds.cern.ch/record/2318948?ln=bg" /> <link rel="alternate" hreflang="zh-TW" href="https://cds.cern.ch/record/2318948?ln=zh_TW" /> <link rel="alternate" hreflang="pt" href="https://cds.cern.ch/record/2318948?ln=pt" /> <link rel="alternate" hreflang="no" href="https://cds.cern.ch/record/2318948?ln=no" /> <link rel="alternate" hreflang="hr" href="https://cds.cern.ch/record/2318948?ln=hr" /> <link rel="alternate" hreflang="ca" href="https://cds.cern.ch/record/2318948?ln=ca" /> <link rel="alternate" hreflang="de" href="https://cds.cern.ch/record/2318948?ln=de" /> <link rel="alternate" hreflang="it" href="https://cds.cern.ch/record/2318948?ln=it" /> <link rel="alternate" hreflang="zh-CN" href="https://cds.cern.ch/record/2318948?ln=zh_CN" /> <link rel="alternate" hreflang="sv" href="https://cds.cern.ch/record/2318948?ln=sv" /> <link rel="alternate" hreflang="sk" href="https://cds.cern.ch/record/2318948?ln=sk" /> <link rel="alternate" hreflang="en" href="https://cds.cern.ch/record/2318948?ln=en" /> <link rel="alternate" hreflang="pl" href="https://cds.cern.ch/record/2318948?ln=pl" /> <link rel="alternate" hreflang="ru" href="https://cds.cern.ch/record/2318948?ln=ru" /> <link rel="alternate" hreflang="ka" href="https://cds.cern.ch/record/2318948?ln=ka" /> <link rel="alternate" hreflang="ja" href="https://cds.cern.ch/record/2318948?ln=ja" /> <link rel="alternate" hreflang="es" href="https://cds.cern.ch/record/2318948?ln=es" /> <link rel="alternate" type="application/rss+xml" title="CERN Document Server RSS" href="/rss?ln=zh_CN" /> <link rel="search" type="application/opensearchdescription+xml" href="https://cds.cern.ch/opensearchdescription" title="CERN Document Server" /> <link rel="unapi-server" type="application/xml" title="unAPI" href="https://cds.cern.ch/unapi" /> <link rel="apple-touch-icon" href="/apple-touch-icon.png"/> <link rel="apple-touch-icon-precomposed" href="/apple-touch-icon-precomposed.png"/> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta http-equiv="Content-Language" content="zh_CN" /> <meta name="description" content="We present the results of numerical simulations and experimental studies about the effects of resonant and random excitations on proton losses, emittances, and beam distributions in the Large Hadron Collider (LHC). In addition to shedding light on complex nonlinear effects, these studies are applied to the design of hollow electron lenses for active beam halo control. In the High-Luminosity Large Hadron Collider (HL-LHC), a considerable amount of energy will be stored in the beam tails. To control and clean the beam halo, the installation of two hollow electron lenses, one per beam, is being considered. In standard electron-lens operation, a proton bunch sees the same electron current at every revolution. Pulsed electron beam operation (i.e., different currents for different turns) is also considered, because it can widen the range of achievable halo removal rates. For an axially symmetric electron beam, only protons in the halo are excited. If a residual field is present at the location of the beam core, these particles are exposed to time-dependent transverse kicks and to noise. We discuss the numerical simulations and the experiments conducted in 2016 and 2017 at injection energy in the LHC. The excitation patterns were generated by the transverse feedback and damping system, which acted as a flexible source of dipole kicks. Proton beam losses, emittances, and transverse distributions were recorded as a function of excitation patterns and strengths. The resonant excitations induced rich dynamical effects and nontrivial changes of the beam distributions, which, to our knowledge, have not previously been observed and studied in this detail. We conclude with a discussion of the tolerable and achievable residual fields and proposals for further studies. We present the results of numerical simulations and experimental studies about the effects of resonant and random excitations on proton losses, emittances, and beam distributions in the Large Hadron Collider (LHC). In addition to shedding light on complex nonlinear effects, these studies are applied to the design of hollow electron lenses (HEL) for active beam halo control. In the High-Luminosity Large Hadron Collider (HL-LHC), a considerable amount of energy will be stored in the beam tails. To control and clean the beam halo, the installation of two hollow electron lenses, one per beam, is being considered. In standard electron-lens operation, a proton bunch sees the same electron current at every revolution. Pulsed electron beam operation (i.e., different currents for different turns) is also considered, because it can widen the range of achievable halo removal rates. For an axially symmetric electron beam, only protons in the halo are excited. If a residual field is present at the location of the beam core, these particles are exposed to time-dependent transverse kicks and to noise. We discuss the numerical simulations and the experiments conducted in 2016 and 2017 at injection energy in the LHC. The excitation patterns were generated by the transverse feedback and damping system, which acted as a flexible source of dipole kicks. Proton beam losses, emittances, and transverse distributions were recorded as a function of excitation patterns and strengths. The resonant excitations induced rich dynamical effects and nontrivial changes of the beam distributions, which, to our knowledge, have not previously been observed and studied in this detail. We conclude with a discussion of the tolerable and achievable residual fields and proposals for further studies. Fitterer, Miriam; Stancari, Giulio; Valishev, Alexander; Redaelli, Stefano; Valuch, Daniel" /> <meta name="keywords" content="CERN Document Server, WebSearch, CERN Document Server" /> <script type="text/javascript" src="https://cds.cern.ch/js/jquery.min.js"></script>  <link rel="stylesheet" href="https://cds.cern.ch/img/webnews.css" type="text/css" />  <script type="text/javascript" src="https://cds.cern.ch/js/webnews.js?v=20131009"></script> <meta property="fb:app_id" content="137353533001720"/> <script type="text/x-mathjax-config"> MathJax.Hub.Config({ tex2jax: {inlineMath: [['$','$']], processEscapes: true}, showProcessingMessages: false, messageStyle: "none" }); </script> <script src="/MathJax/MathJax.js?config=TeX-AMS_CHTML" type="text/javascript"> </script>  <meta content="arXiv : Resonant and random excitations on the proton beam in the Large Hadron Collider for active halo control with pulsed hollow electron lenses" name="citation_title" /> <meta content="Fitterer, Miriam" name="citation_author" /> <meta content="Stancari, Giulio" name="citation_author" /> <meta content="Redaelli, Stefano" name="citation_author" /> <meta content="Valishev, Alexander" name="citation_author" /> <meta content="Valuch, Daniel" name="citation_author" /> <meta content="10.1103/PhysRevAccelBeams.24.021001" name="citation_doi" /> <meta content="Phys. 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Beams" name="citation_journal_title" /> <meta content="24" name="citation_volume" /> <meta content="021001" name="citation_firstpage" /> <meta content="2018/04/19" name="citation_publication_date" /> <meta name="citation_online_date" content="2018/05/19"> <meta content="arXiv:1804.07418" name="citation_technical_report_number" /> <meta content="FERMILAB-PUB-18-084-AD-APC" name="citation_technical_report_number" /> <meta content="FERMILAB-PUB-21-008-AD" name="citation_technical_report_number" /> <meta content="10.1103/PhysRevAccelBeams.24.021001" name="citation_doi" /> <meta name="citation_pdf_url" content="https://cds.cern.ch/record/2318948/files/10.1103_PhysRevAccelBeams.24.021001.pdf" /> <meta name="citation_pdf_url" content="https://cds.cern.ch/record/2318948/files/PhysRevAccelBeams.24.pdf" /> <meta name="citation_pdf_url" content="https://cds.cern.ch/record/2318948/files/fermilab-pub-18-084-ad-apc.pdf" /> <meta name="citation_pdf_url" 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content="https://cds.cern.ch/record/2318948/files/2017_emith_avg_rel_hv7th_no_damper.png" /> <meta property="og:image:secure_url" content="https://cds.cern.ch/record/2318948/files/2017_emith_avg_rel_hv7th_no_damper.png" /> <meta property="og:image" content="https://cds.cern.ch/record/2318948/files/2017_scale_amp_7v_lblshort.png" /> <meta property="og:image:secure_url" content="https://cds.cern.ch/record/2318948/files/2017_scale_amp_7v_lblshort.png" /> <meta property="og:image" content="https://cds.cern.ch/record/2318948/files/2016injnocolc15o+19_6noerrut7skh_dp0_ord7.png" /> <meta property="og:image:secure_url" content="https://cds.cern.ch/record/2318948/files/2016injnocolc15o+19_6noerrut7skh_dp0_ord7.png" /> <meta content="CERN Document Server" property="og:site_name" /> <meta content="APS" property="og:description" /> <meta content="arXiv" property="og:description" /> <meta content="We present the results of numerical simulations and experimental studies about the effects of resonant and random excitations on proton losses, emittances, and beam distributions in the Large Hadron Collider (LHC). In addition to shedding light on complex nonlinear effects, these studies are applied to the design of hollow electron lenses for active beam halo control. In the High-Luminosity Large Hadron Collider (HL-LHC), a considerable amount of energy will be stored in the beam tails. To control and clean the beam halo, the installation of two hollow electron lenses, one per beam, is being considered. In standard electron-lens operation, a proton bunch sees the same electron current at every revolution. Pulsed electron beam operation (i.e., different currents for different turns) is also considered, because it can widen the range of achievable halo removal rates. For an axially symmetric electron beam, only protons in the halo are excited. If a residual field is present at the location of the beam core, these particles are exposed to time-dependent transverse kicks and to noise. We discuss the numerical simulations and the experiments conducted in 2016 and 2017 at injection energy in the LHC. The excitation patterns were generated by the transverse feedback and damping system, which acted as a flexible source of dipole kicks. Proton beam losses, emittances, and transverse distributions were recorded as a function of excitation patterns and strengths. The resonant excitations induced rich dynamical effects and nontrivial changes of the beam distributions, which, to our knowledge, have not previously been observed and studied in this detail. We conclude with a discussion of the tolerable and achievable residual fields and proposals for further studies." property="og:description" /> <meta content="We present the results of numerical simulations and experimental studies about the effects of resonant and random excitations on proton losses, emittances, and beam distributions in the Large Hadron Collider (LHC). In addition to shedding light on complex nonlinear effects, these studies are applied to the design of hollow electron lenses (HEL) for active beam halo control. In the High-Luminosity Large Hadron Collider (HL-LHC), a considerable amount of energy will be stored in the beam tails. To control and clean the beam halo, the installation of two hollow electron lenses, one per beam, is being considered. In standard electron-lens operation, a proton bunch sees the same electron current at every revolution. Pulsed electron beam operation (i.e., different currents for different turns) is also considered, because it can widen the range of achievable halo removal rates. For an axially symmetric electron beam, only protons in the halo are excited. If a residual field is present at the location of the beam core, these particles are exposed to time-dependent transverse kicks and to noise. We discuss the numerical simulations and the experiments conducted in 2016 and 2017 at injection energy in the LHC. The excitation patterns were generated by the transverse feedback and damping system, which acted as a flexible source of dipole kicks. Proton beam losses, emittances, and transverse distributions were recorded as a function of excitation patterns and strengths. The resonant excitations induced rich dynamical effects and nontrivial changes of the beam distributions, which, to our knowledge, have not previously been observed and studied in this detail. We conclude with a discussion of the tolerable and achievable residual fields and proposals for further studies." property="og:description" />  <meta content="summary" name="twitter:card" /> <style></style> </head> <body class="CERN32Document32Server search" lang="zh">  <div id="cern-toolbar"> <h1><a href="http://cern.ch" title="CERN">CERN <span>Accelerating science</span></a></h1> <ul> <li class="cern-accountlinks"><a class="cern-account" href="https://cds.cern.ch/youraccount/login?ln=zh_CN&referer=https%3A//cds.cern.ch/record/2318948%3Fln%3Dzh_CN" title="Sign in to your CERN account">Sign in</a></li> <li><a class="cern-directory" href="http://cern.ch/directory" title="Search CERN resources and browse the directory">Directory</a></li> </ul> </div>   <div role="banner" class="clearfix" id="header"> <div class="header-inner inner"> <hgroup class="clearfix"> <h2 id="site-name"> <a rel="home" title="Home" href="/"><span>CERN Document Server</span></a> </h2> <h3 id="site-slogan">Access articles, reports and multimedia content in HEP</h3> </hgroup> <div role="navigation" id="main-navigation" class="cdsmenu"> <h2 class="element-invisible">Main menu</h2><ul class="links inline clearfix"> <li class="menu-386 first active-trail"><a class="active-trail" href="https://cds.cern.ch/?ln=zh_CN">搜寻</a></li> <li class="menu-444 "><a class="" title="" href="https://cds.cern.ch/submit?ln=zh_CN">提交</a></li> <li class="menu-426 "><a class="" href="https://cds.cern.ch/help/?ln=zh_CN">帮助</a></li> <li class="leaf hassubcdsmenu"> <a hreflang="en" class="header" href="https://cds.cern.ch/youraccount/display?ln=zh_CN">个人化</a> <ul class="subsubcdsmenu"><li><a href="https://cds.cern.ch/youralerts/list?ln=zh_CN">Your alerts</a></li><li><a href="https://cds.cern.ch/yourbaskets/display?ln=zh_CN">Your baskets</a></li><li><a href="https://cds.cern.ch/yourcomments?ln=zh_CN">Your comments</a></li><li><a href="https://cds.cern.ch/youralerts/display?ln=zh_CN">Your searches</a></li></ul></li> </ul> </div> </div> </div>  <table class="navtrailbox"> <tr> <td class="navtrailboxbody"> <a href="/?ln=zh_CN" class="navtrail">主页</a> > Resonant and random excitations on the proton beam in the Large Hadron Collider for active halo control with pulsed hollow electron lenses </td> </tr> </table> </div> <div class="pagebody"><div class="pagebodystripemiddle"> <div class="detailedrecordbox"> <div class="detailedrecordtabs"> <div> <ul class="detailedrecordtabs"><li class="on first"><a href="/record/2318948/?ln=zh_CN">Information </a></li><li class=""><a href="/record/2318948/files?ln=zh_CN">Files </a></li></ul> <div id="tabsSpacer" style="clear:both;height:0px"> </div></div> </div> <div class="detailedrecordboxcontent"> <div class="top-left-folded"></div> <div class="top-right-folded"></div> <div class="inside">  <abbr class="unapi-id" title="2318948"></abbr> <style type="text/css">  </style> <table class="formatRecordTableFullWidth" > <tr> <td class="formatRecordHeader" style="background-image: url('https://cds.cern.ch/img/journals.jpg');" colspan="2">  Article </td> </tr> <script type="text/javascript"> $( document ).ready(function() { $('.showAuthor').on('click', function() { var author = '<p>' + $(this).data('name') + '</p>'; var affiliation = $(this).data('affiliation') + '</br>'; var contribution = $(this).data('contribution') + '</br>'; $.magnificPopup.open({ items: { src: '<div id="ovelary-mathjax" class="overlay-white oc-content overlay-white-500">' + author + affiliation + contribution + '</div>', type: 'inline' }, callbacks: { open: function() { var div = document.getElementById("overlay-mathjax") MathJax.Hub.Queue(["Typeset", MathJax.Hub, div]); }, } }) }) }); </script> <tr><td class="formatRecordLabel"> Report number </td><td style="padding-left:5px;"><a href="http://arxiv.org/abs/arXiv:1804.07418">arXiv:1804.07418</a> ; FERMILAB-PUB-18-084-AD-APC ; FERMILAB-PUB-21-008-AD</td></tr> <tr><td class="formatRecordLabel"> Title </td><td style="padding-left:5px;"><b>Resonant and random excitations on the proton beam in the Large Hadron Collider for active halo control with pulsed hollow electron lenses</b></td></tr> <tr><td class="formatRecordLabel" style="vertical-align:top;">Related title</td><td style="padding-left:5px; ">Effects of Resonant and Random Excitations on the Proton Beam in the Large Hadron Collider, with Applications to the Design of Pulsed Hollow Electron Lenses for Active Halo Control<br/></td></tr> <tr><td class="formatRecordLabel"><span style="white-space:nowrap;"> Author(s) </span> </td><td style="padding-left:5px;"><a href="https://cds.cern.ch/search?f=author&p=Fitterer%2C%20Miriam&ln=zh_CN">Fitterer, Miriam</a> (Fermilab) ; <a href="https://cds.cern.ch/search?f=author&p=Stancari%2C%20Giulio&ln=zh_CN">Stancari, Giulio</a> (Fermilab) ; <a href="https://cds.cern.ch/search?f=author&p=Valishev%2C%20Alexander&ln=zh_CN">Valishev, Alexander</a> (Fermilab) ; <a href="https://cds.cern.ch/search?f=author&p=Redaelli%2C%20Stefano&ln=zh_CN">Redaelli, Stefano</a> (CERN) ; <a href="https://cds.cern.ch/search?f=author&p=Valuch%2C%20Daniel&ln=zh_CN">Valuch, Daniel</a> (CERN)</td></tr> <tr><td class="formatRecordLabel"> Publication </td><td style="padding-left:5px;">2021-02-12</td></tr> <tr><td class="formatRecordLabel"> Imprint </td><td style="padding-left:5px;">2018-04-19</td></tr> <tr><td class="formatRecordLabel"> Number of pages </td><td style="padding-left:5px;">24</td></tr> <tr><td class="formatRecordLabel"> Note </td><td style="padding-left:5px;">33 pages, 32 figures, 46 references. Revised manuscript submitted to Phys. Rev. Accel. Beams</td></tr> <tr><td class="formatRecordLabel"> In: </td><td style="padding-left:5px;"><a href="http://dx.doi.org/10.1103/PhysRevAccelBeams.24.021001"><i>Phys. Rev. Accel. Beams</i> 24 (2021) 021001</a> </a></td></tr> <tr><td class="formatRecordLabel"> DOI </td><td style="padding-left:5px;"><a href="http://dx.doi.org/10.1103/PhysRevAccelBeams.24.021001" title="DOI" target="_blank">10.1103/PhysRevAccelBeams.24.021001</a> <tr><td class="formatRecordLabel"> Subject category </td><td style="padding-left:5px;">physics.acc-ph ; Accelerators and Storage Rings</td></tr> <tr><td class="formatRecordLabel"> Accelerator/Facility, Experiment </td><td style="padding-left:5px;"><a href="https://cds.cern.ch/search?p=CERN%20LHC&f=693__a">CERN LHC</a></td></tr> <tr><td class="formatRecordLabel"> Project </td><td style="padding-left:5px;"><a href='https://cds.cern.ch/search?p=693__p:"CERN HL-LHC"'>CERN HL-LHC</a></td></tr> <tr><td class="formatRecordLabel"> Abstract </td><td style="padding-left:5px;">We present the results of numerical simulations and experimental studies about the effects of resonant and random excitations on proton losses, emittances, and beam distributions in the Large Hadron Collider (LHC). In addition to shedding light on complex nonlinear effects, these studies are applied to the design of hollow electron lenses (HEL) for active beam halo control. In the High-Luminosity Large Hadron Collider (HL-LHC), a considerable amount of energy will be stored in the beam tails. To control and clean the beam halo, the installation of two hollow electron lenses, one per beam, is being considered. In standard electron-lens operation, a proton bunch sees the same electron current at every revolution. Pulsed electron beam operation (i.e., different currents for different turns) is also considered, because it can widen the range of achievable halo removal rates. For an axially symmetric electron beam, only protons in the halo are excited. If a residual field is present at the location of the beam core, these particles are exposed to time-dependent transverse kicks and to noise. We discuss the numerical simulations and the experiments conducted in 2016 and 2017 at injection energy in the LHC. The excitation patterns were generated by the transverse feedback and damping system, which acted as a flexible source of dipole kicks. Proton beam losses, emittances, and transverse distributions were recorded as a function of excitation patterns and strengths. The resonant excitations induced rich dynamical effects and nontrivial changes of the beam distributions, which, to our knowledge, have not previously been observed and studied in this detail. We conclude with a discussion of the tolerable and achievable residual fields and proposals for further studies.</td></tr> <tr><td class="formatRecordLabel"> Copyright/License </td><td style="padding-left:5px;">preprint: (License: <a href="http://arxiv.org/licenses/nonexclusive-distrib/1.0/">arXiv nonexclusive-distrib 1.0</a>)<br/>publication: © 2021-2025 authors (License: <a href="https://creativecommons.org/licenses/by/4.0/">CC-BY-4.0</a>)</td></tr> </table> <br /><div style="max-width:1024px;margin:auto"><div style="overflow-x:auto;display:inline;width:100%;"><a href="/record/2318948/plots#0"><img style="vertical-align:middle;" src="https://cds.cern.ch/record/2318948/files/2016_emitv_avg_rel_v10th_with_damper_no_text.png" title=" Comparison of measured vertical emittances for bunches with transverse damper off (top row) and with transverse damper on (bottom row), during random V excitations (left), \seventhtp\ in V (center) and \tenthtp\ in V (right). (Because of a change in experimental setup, for the bunches represented by the yellow line in the bottom right plot, the excitation was zero instead of the maximum value.)" width="200px"/></a> <a href="/record/2318948/plots#1"><img style="vertical-align:middle;" src="https://cds.cern.ch/record/2318948/files/2017_bunch_intensity_vran_no_damper_avg.png" title=" Measured effects of the random excitation (in V, top row; and H+V, bottom row) during the 2017 experiment: relative intensity losses (left), relative horizontal emittance (center), and relative vertical emittance (right)." width="200px"/></a> <a href="/record/2318948/plots#2"><img style="vertical-align:middle;" src="https://cds.cern.ch/record/2318948/files/2017_scale_amp_ranhv_lblshort.png" title=" Measured loss rates as a function of amplitude for random excitations in H only (left), V only (center), and H+V (right). For each of the three excitation modes, three consecutive data sets were taken (black, red, and yellow), with increasing maximum amplitude. Data were taken simultaneously with no transverse damper on some bunches (filled circles and solid lines) and with the damper active on other bunches (empty circles and dashed lines). The lines represent empirical second-order polynomial fits." width="200px"/></a> <a href='/record/2318948/plots'>Show more plots</a></div></div><br /> <br/>Corresponding record in: <a href="http://inspirehep.net/record/1669307">Inspire</a> <small> </small> <br/> <br/><br/><div align="right"><div style="padding-bottom:2px;padding-top:30px;"><span class="moreinfo" style="margin-right:10px;"> <a href="" class="moreinfo">Back to search</a> </span></div></div> <div class="bottom-left-folded"><div class="recordlastmodifiedbox" style="position:relative;margin-left:1px"> 记录创建於2018-05-19，最後更新在2024-08-08</div></div> <div class="bottom-right-folded" style="text-align:right;padding-bottom:2px;"> <span class="moreinfo" style="margin-right:10px;"><a href="/search?ln=zh_CN&p=recid%3A2318948&rm=wrd" class="moreinfo">相似记录</a></span></div> </div> </div> </div> <br/> <br /> <div class="detailedrecordminipanel"> <div class="top-left"></div><div class="top-right"></div> <div class="inside"> <div id="detailedrecordminipanelfile" style="width:33%;float:left;text-align:center;margin-top:0"> <div><small class="detailedRecordActions">Fulltext from Publisher:</small> <br /><a href="/record/2318948/files/10.1103_PhysRevAccelBeams.24.021001.pdf"><img style="border:none" src="/img/file-icon-text-12x16.gif" alt="Download fulltext"/>PDF</a><br /></div><div><small class="detailedRecordActions">Fulltext from publisher:</small> <br /><a href="/record/2318948/files/PhysRevAccelBeams.24.pdf"><img style="border:none" src="/img/file-icon-text-12x16.gif" alt="Download fulltext"/>PDF</a><br /></div><div><small class="detailedRecordActions">全文:</small> <br /><em>fermilab-pub-18-084-ad-apc</em> - <a href="/record/2318948/files/fermilab-pub-18-084-ad-apc.pdf"><img style="border:none" src="/img/file-icon-text-12x16.gif" alt="Download fulltext"/>PDF</a><br /><em>1804.07418</em> - <a href="/record/2318948/files/1804.07418.pdf"><img style="border:none" src="/img/file-icon-text-12x16.gif" alt="Download fulltext"/>PDF</a><br /></div><small class="detailedRecordActions">External links:</small><br /><small><a href="http://lss.fnal.gov/archive/2018/pub/fermilab-pub-18-084-ad-apc.pdf"><img style="border:none" src="/img/file-icon-text-12x16.gif" alt="Download fulltext"/>Fermilab Library Server (fulltext available)</a><br /><a href="https://lss.fnal.gov/archive/2021/pub/fermilab-pub-21-008-ad.pdf"><img style="border:none" src="/img/file-icon-text-12x16.gif" alt="Download fulltext"/>Fermilab Accepted Manuscript</a></small> </div> <div id="detailedrecordminipanelreview" style="width:30%;float:left;text-align:center"> </div> <div id="detailedrecordminipanelactions" style="width:36%;float:right;text-align:right;"> <ul class="detailedrecordactions"> <li><a href="/yourbaskets/add?ln=zh_CN&recid=2318948">Add to personal basket</a></li> <li>Export as <a style="text-decoration:underline;font-weight:normal" href="/record/2318948/export/hx?ln=zh_CN">BibTeX</a>, <a style="text-decoration:underline;font-weight:normal" href="/record/2318948/export/hm?ln=zh_CN">MARC</a>, <a style="text-decoration:underline;font-weight:normal" href="/record/2318948/export/xm?ln=zh_CN">MARCXML</a>, <a style="text-decoration:underline;font-weight:normal" href="/record/2318948/export/xd?ln=zh_CN">DC</a>, <a style="text-decoration:underline;font-weight:normal" href="/record/2318948/export/xe?ln=zh_CN">EndNote</a>,  <a style="text-decoration:underline;font-weight:normal" href="/record/2318948/export/xn?ln=zh_CN">NLM</a>, <a style="text-decoration:underline;font-weight:normal" href="/record/2318948/export/xw?ln=zh_CN">RefWorks</a> </li> </ul> <div style='padding-left: 13px;'>  <div id="bookmark"></div> <div id="bookmark_sciencewise"></div> <style type="text/css"> #bookmark_sciencewise, #bookmark {float: left;} #bookmark_sciencewise li {padding: 2px; width: 25px;} #bookmark_sciencewise ul, #bookmark ul {list-style-image: none;} </style> <script type="text/javascript" src="/js/jquery.bookmark.min.js"></script> <style type="text/css">@import "/css/jquery.bookmark.css";</style> <script type="text/javascript">// <![CDATA[ $.bookmark.addSite('sciencewise', 'ScienceWise.info', 'https://cds.cern.ch/img/sciencewise.png', 'en', 'bookmark', 'http://sciencewise.info/bookmarks/1804.0741/add'); $('#bookmark_sciencewise').bookmark({sites: ['sciencewise']}); $('#bookmark').bookmark({ sites: ['facebook', 'twitter', 'linkedin', 'google_plusone'], icons: '/img/bookmarks.png', url: 'https://cds.cern.ch/record/2318948', addEmail: true, title: "Resonant and random excitations on the proton beam in the Large Hadron Collider for active halo control with pulsed hollow electron lenses", description: "We present the results of numerical simulations and experimental studies about the effects of resonant and random excitations on proton losses, emittances, and beam distributions in the Large Hadron Collider (LHC). In addition to shedding light on complex nonlinear effects, these studies are applied to the design of hollow electron lenses for active beam halo control. In the High-Luminosity Large Hadron Collider (HL-LHC), a considerable amount of energy will be stored in the beam tails. To control and clean the beam halo, the installation of two hollow electron lenses, one per beam, is being considered. In standard electron-lens operation, a proton bunch sees the same electron current at every revolution. Pulsed electron beam operation (i.e., different currents for different turns) is also considered, because it can widen the range of achievable halo removal rates. For an axially symmetric electron beam, only protons in the halo are excited. If a residual field is present at the location of the beam core, these particles are exposed to time-dependent transverse kicks and to noise. We discuss the numerical simulations and the experiments conducted in 2016 and 2017 at injection energy in the LHC. The excitation patterns were generated by the transverse feedback and damping system, which acted as a flexible source of dipole kicks. Proton beam losses, emittances, and transverse distributions were recorded as a function of excitation patterns and strengths. The resonant excitations induced rich dynamical effects and nontrivial changes of the beam distributions, which, to our knowledge, have not previously been observed and studied in this detail. 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