Uncontrolled Longitudinal Emittance Blow-Up during RF Manipulations in the CERN PS

<!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="pt" xml:lang="pt" xmlns:og="http://ogp.me/ns#" xmlns:fb="http://ogp.me/ns/fb#"> <head> <title>Uncontrolled Longitudinal Emittance Blow-Up during RF Manipulations in the CERN PS - 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="http://cds.cern.ch/img/invenio.css?v=20141127" type="text/css" /> <link rel="stylesheet" href="http://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="http://cds.cern.ch/img/cern_toolbar/css/toolbar.css" type="text/css" />    <link rel="canonical" href="http://cds.cern.ch/record/2646057/files/" /> <link rel="alternate" hreflang="el" href="http://cds.cern.ch/record/2646057/files/?ln=el" /> <link rel="alternate" hreflang="fr" href="http://cds.cern.ch/record/2646057/files/?ln=fr" /> <link rel="alternate" hreflang="bg" href="http://cds.cern.ch/record/2646057/files/?ln=bg" /> <link rel="alternate" hreflang="zh-TW" href="http://cds.cern.ch/record/2646057/files/?ln=zh_TW" /> <link rel="alternate" hreflang="pt" href="http://cds.cern.ch/record/2646057/files/?ln=pt" /> <link rel="alternate" hreflang="no" href="http://cds.cern.ch/record/2646057/files/?ln=no" /> <link rel="alternate" hreflang="hr" href="http://cds.cern.ch/record/2646057/files/?ln=hr" /> <link rel="alternate" hreflang="ca" href="http://cds.cern.ch/record/2646057/files/?ln=ca" /> <link rel="alternate" hreflang="de" href="http://cds.cern.ch/record/2646057/files/?ln=de" /> <link rel="alternate" hreflang="it" href="http://cds.cern.ch/record/2646057/files/?ln=it" /> <link rel="alternate" hreflang="zh-CN" href="http://cds.cern.ch/record/2646057/files/?ln=zh_CN" /> <link rel="alternate" hreflang="sv" href="http://cds.cern.ch/record/2646057/files/?ln=sv" /> <link rel="alternate" hreflang="sk" href="http://cds.cern.ch/record/2646057/files/?ln=sk" /> <link rel="alternate" hreflang="en" href="http://cds.cern.ch/record/2646057/files/?ln=en" /> <link rel="alternate" hreflang="pl" href="http://cds.cern.ch/record/2646057/files/?ln=pl" /> <link rel="alternate" hreflang="ru" href="http://cds.cern.ch/record/2646057/files/?ln=ru" /> <link rel="alternate" hreflang="ka" href="http://cds.cern.ch/record/2646057/files/?ln=ka" /> <link rel="alternate" hreflang="ja" href="http://cds.cern.ch/record/2646057/files/?ln=ja" /> <link rel="alternate" hreflang="es" href="http://cds.cern.ch/record/2646057/files/?ln=es" /> <link rel="alternate" type="application/rss+xml" title="CERN Document Server RSS" href="http://cds.cern.ch/rss" /> <link rel="search" type="application/opensearchdescription+xml" href="http://cds.cern.ch/opensearchdescription" title="CERN Document Server" /> <link rel="unapi-server" type="application/xml" title="unAPI" href="http://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="pt" /> <meta name="description" content="The CERN Proton Synchrotron (PS) determines the basic bunch spacing for the Large Hadron Collider (LHC) by means of rf manipulations. Several rf systems in a frequency range from 2.8 MHz to 200 MHz are available for beam acceleration and manipulations. Each of the six bunches injected from the PS Booster is split in several steps into 12 bunches spaced by 25 ns, yielding a batch of 72 bunches at transfer to the Super Proton Synchrotron (SPS). In the framework of the LHC Injector Upgrade (LIU) project the bunch intensity must be doubled. However, with most of the planned upgrades already in place this intensity has not yet been achieved due to collective effects. One of them is uncontrolled longitudinal emittance blow-up during the bunch splittings. In this contribution, measurements of the blow-up during the splitting process are presented and compared with particle simulations using the present PS impedance model. Beam-based measurements of the impedances of the rf cavities have been performed. They revealed that to reproduce the instability an additional impedance source is required in the PS impedance model. The CERN Proton Synchrotron (PS) determines the basic bunch spacing for the Large Hadron Collider (LHC) by means of rf manipulations. Several rf systems in a frequency range from 2.8 MHz to 200 MHz are available for beam acceleration and manipulations. Each of the six bunches injected from the PS Booster is split in several steps into 12 bunches spaced by 25 ns, yielding a batch of 72 bunches at transfer to the Super Proton Synchrotron (SPS). In the framework of the LHC Injector Upgrade (LIU) project the bunch intensity must be doubled. However, with most of the planned upgrades already in place this intensity has not yet been achieved due to collective effects. One of them is uncontrolled longitudinal emittance blowup during the bunch splittings. In this contribution, measurements of the blow-up during the splitting process are presented and compared with particle simulations using the present PS impedance model. Beam-based measurements of the impedances of the rf cavities have been performed. They revealed that to reproduce the instability an additional impedance source is required in the PS impedance model. Lasheen, Alexandre; Damerau, Heiko; Favia, Giorgia" /> <meta name="keywords" content="impedance, cavity, emittance, simulation, controls" /> <script type="text/javascript" src="http://cds.cern.ch/js/jquery.min.js"></script>  <link rel="stylesheet" href="http://cds.cern.ch/img/webnews.css" type="text/css" />  <script type="text/javascript" src="http://cds.cern.ch/js/webnews.js?v=20131009"></script> <meta property="fb:app_id" content="137353533001720"/> <style></style> </head> <body class="search" lang="pt">  <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=pt&referer=http%3A//cds.cern.ch/record/2646057/files/%3Fln%3Dpt" 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="http://cds.cern.ch/?ln=pt">Pesquisar</a></li> <li class="menu-444 "><a class="" title="" href="http://cds.cern.ch/submit?ln=pt">Submeter</a></li> <li class="menu-426 "><a class="" href="http://cds.cern.ch/help/?ln=pt">Ajuda</a></li> <li class="leaf hassubcdsmenu"> <a hreflang="en" class="header" href="https://cds.cern.ch/youraccount/display?ln=pt">Personalizar</a> <ul class="subsubcdsmenu"><li><a href="https://cds.cern.ch/youralerts/list?ln=pt">Your alerts</a></li><li><a href="https://cds.cern.ch/yourbaskets/display?ln=pt">Your baskets</a></li><li><a href="https://cds.cern.ch/yourcomments?ln=pt">Your comments</a></li><li><a href="https://cds.cern.ch/youralerts/display?ln=pt">Your searches</a></li></ul></li> </ul> </div> </div> </div>  <table class="navtrailbox"> <tr> <td class="navtrailboxbody"> <a href="/?ln=pt" class="navtrail">Página principal</a> > > <a class="navtrail" href="http://cds.cern.ch/record/2646057">Uncontrolled Longitudinal Emittance Blow-Up during RF Manipulations in the CERN PS</a> > Acesso a Fulltext </td> </tr> </table> </div> <div class="pagebody"><div class="pagebodystripemiddle"> <div class="detailedrecordbox"> <div class="detailedrecordtabs"> <div> <ul class="detailedrecordtabs"><li class="first"><a href="http://cds.cern.ch/record/2646057/?ln=pt">Informação </a></li><li class="on"><a href="http://cds.cern.ch/record/2646057/files?ln=pt">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">  <div id="detailedrecordshortreminder"> <div id="clip"> </div> <div id="HB"> <strong><a href="/record/2646057?ln=pt">Uncontrolled Longitudinal Emittance Blow-Up during RF Manipulations in the CERN PS</a></strong> - <a href="/search?f=author&p=Lasheen%2C%20Alexandre&ln=pt">Lasheen, Alexandre</a> <em>et al</em> </div> </div> <div style="clear:both;height:1px"> </div> <div style="width:90%;margin:auto;min-height:100px;margin-top:10px">  <small><b>Main</b> ficheiro(s):</small><ul><table border="0" cellspacing="1" class="searchbox"> <tr> <td align="left" colspan="2" class="portalboxheader"> <img src='http://cds.cern.ch/img/smallfiles.gif' border="0" />  thpaf041 </td> </tr><tr> <td class="portalboxheader"> <font size="-2">version 1</font> </td> <td> <table> <tr> <td valign="top"> <small><a href="http://cds.cern.ch/record/2646057/files/thpaf041.pdf?version=1">thpaf041.pdf</a></small> </td> <td valign="top"> <font size="-2" color="green">[877.59 KB]</font> <font size="-2"><em>06 Novembro 2018, 06:56</em> </td> <td valign="top"><em></em></td> </tr></table></td></tr></table></ul> </div> <div class="bottom-left-folded"></div> <div class="bottom-right-folded" style="text-align:right;padding-bottom:2px;"> <span class="moreinfo" style="margin-right:10px;"><a href="/search?ln=pt&p=recid%3A2646057&rm=wrd" class="moreinfo">Registos similares</a></span></div> </div> </div> </div> <br/> </div></div> <footer id="footer" class="pagefooter clearfix">  <div class="pagefooterstripeleft"> CERN Document Server :: <a class="footer" href="http://cds.cern.ch/?ln=pt">Pesquisar</a> :: <a class="footer" href="http://cds.cern.ch/submit?ln=pt">Submeter</a> :: <a class="footer" href="https://cds.cern.ch/youraccount/display?ln=pt">Personalizar</a> :: <a class="footer" href="http://cds.cern.ch/help/?ln=pt">Ajuda</a> :: <a class="footer" href="https://cern.service-now.com/service-portal?id=privacy_policy&se=CDS-Service" target="_blank">Privacy Notice</a> <br /> Powered by <a class="footer" href="http://invenio-software.org/">Invenio</a> <br /> Mantido por <a class="footer" href="https://cern.service-now.com/service-portal?id=service_element&name=CDS-Service">CDS Service</a> - 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Uncontrolled Longitudinal Emittance Blow-Up during RF Manipulations in the CERN PS - CERN Document Server