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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="de" xml:lang="de" xmlns:og="http://ogp.me/ns#" xmlns:fb="http://ogp.me/ns/fb#"> <head> <title>Degradation and Recovery of the LHC RF Cryomodule Performance Using the Helium Processing Technique - 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/2846167/export/hm" /> <link rel="alternate" hreflang="el" href="https://cds.cern.ch/record/2846167/export/hm?ln=el" /> <link rel="alternate" hreflang="fr" href="https://cds.cern.ch/record/2846167/export/hm?ln=fr" /> <link rel="alternate" hreflang="bg" href="https://cds.cern.ch/record/2846167/export/hm?ln=bg" /> <link rel="alternate" hreflang="zh-TW" href="https://cds.cern.ch/record/2846167/export/hm?ln=zh_TW" /> <link rel="alternate" hreflang="pt" href="https://cds.cern.ch/record/2846167/export/hm?ln=pt" /> <link rel="alternate" hreflang="no" href="https://cds.cern.ch/record/2846167/export/hm?ln=no" /> <link rel="alternate" hreflang="hr" href="https://cds.cern.ch/record/2846167/export/hm?ln=hr" /> <link rel="alternate" hreflang="ca" href="https://cds.cern.ch/record/2846167/export/hm?ln=ca" /> <link rel="alternate" hreflang="de" href="https://cds.cern.ch/record/2846167/export/hm?ln=de" /> <link rel="alternate" hreflang="it" href="https://cds.cern.ch/record/2846167/export/hm?ln=it" /> <link rel="alternate" hreflang="zh-CN" href="https://cds.cern.ch/record/2846167/export/hm?ln=zh_CN" /> <link rel="alternate" hreflang="sv" href="https://cds.cern.ch/record/2846167/export/hm?ln=sv" /> <link rel="alternate" hreflang="sk" href="https://cds.cern.ch/record/2846167/export/hm?ln=sk" /> <link rel="alternate" hreflang="en" href="https://cds.cern.ch/record/2846167/export/hm?ln=en" /> <link rel="alternate" hreflang="pl" href="https://cds.cern.ch/record/2846167/export/hm?ln=pl" /> <link rel="alternate" hreflang="ru" href="https://cds.cern.ch/record/2846167/export/hm?ln=ru" /> <link rel="alternate" hreflang="ka" href="https://cds.cern.ch/record/2846167/export/hm?ln=ka" /> <link rel="alternate" hreflang="ja" href="https://cds.cern.ch/record/2846167/export/hm?ln=ja" /> <link rel="alternate" hreflang="es" href="https://cds.cern.ch/record/2846167/export/hm?ln=es" /> <link rel="alternate" type="application/rss+xml" title="CERN Document Server RSS" href="/rss?ln=de" /> <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="de" /> <meta name="description" content="The LHC RF cryomodule "Asia" suffered an accidental influx of about 0.5 l of tunnel air during the leak checks of the pumping manifolds. The resulting risk of particle contamination was difficult to assess, and could not be excluded with certainty. If one or more cavities were contaminated, a severe impact on beam operations in the LHC machine was to be expected. In order to minimize the risks, the Asia cryomodule has been replaced with a spare unit. Subsequently, the cryomodule was tested in the SM18 test facility without intermediate venting, and showed high levels of radiation due to field emission above 1.8 MV in one of the cavities. The other cavities were less strongly affected, but clear signs of contamination were observed. The helium processing technique was used to improve the performance of the SRF cavity with respect to field emission. This paper will discuss the results of the above-mentioned test. Turaj, Katarzyna; Brunner, Olivier; Butterworth, Andrew; Gerigk, Frank; Maesen, Pierre; Montesinos, Eric; Peauger, Franck; Therasse, Mathieu; Venturini Delsolaro, Walter" /> <meta name="keywords" content="cavity, cryomodule, vacuum, radiation, operation" /> <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"/>  <meta content="JACOW : Degradation and Recovery of the LHC RF Cryomodule Performance Using the Helium Processing Technique" name="citation_title" /> <meta content="Turaj, Katarzyna" name="citation_author" /> <meta content="Montesinos, Eric" name="citation_author" /> <meta content="Venturini Delsolaro, Walter" name="citation_author" /> <meta content="Therasse, Mathieu" name="citation_author" /> <meta content="Brunner, Olivier" name="citation_author" /> <meta content="Butterworth, Andrew" name="citation_author" /> <meta content="Peauger, Franck" name="citation_author" /> <meta content="Gerigk, Frank" name="citation_author" /> <meta content="Maesen, Pierre" name="citation_author" /> <meta content="10.18429/JACoW-SRF2021-THPFAV006" name="citation_doi" /> <meta content="JACoW SRF" name="citation_journal_title" /> <meta content="2021" name="citation_volume" /> <meta content="746-750" name="citation_firstpage" /> <meta content="2022" name="citation_publication_date" /> <meta name="citation_online_date" content="2023/01/14"> <meta content="10.18429/JACoW-SRF2021-THPFAV006" name="citation_doi" /> <meta name="citation_pdf_url" content="https://cds.cern.ch/record/2846167/files/document.pdf" />  <meta content="Degradation and Recovery of the LHC RF Cryomodule Performance Using the Helium Processing Technique" property="og:title" /> <meta content="JACOW" property="og:title" /> <meta content="website" property="og:type" /> <meta content="website" property="og:type" /> <meta content="https://cds.cern.ch/record/2846167" property="og:url" /> <meta content="CERN Document Server" property="og:site_name" /> <meta content="JACOW" property="og:description" /> <meta content="The LHC RF cryomodule &quot;Asia&quot; suffered an accidental influx of about 0.5 l of tunnel air during the leak checks of the pumping manifolds. The resulting risk of particle contamination was difficult to assess, and could not be excluded with certainty. If one or more cavities were contaminated, a severe impact on beam operations in the LHC machine was to be expected. In order to minimize the risks, the Asia cryomodule has been replaced with a spare unit. Subsequently, the cryomodule was tested in the SM18 test facility without intermediate venting, and showed high levels of radiation due to field emission above 1.8 MV in one of the cavities. The other cavities were less strongly affected, but clear signs of contamination were observed. The helium processing technique was used to improve the performance of the SRF cavity with respect to field emission. This paper will discuss the results of the above-mentioned test." property="og:description" />  <meta content="summary" name="twitter:card" /> <meta content="summary" name="twitter:card" /> <style></style> </head> <body class="CERN32Document32Server search" lang="de">  <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=de&referer=https%3A//cds.cern.ch/record/2846167/export/hm%3Fln%3Dde" 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=de">Suchen</a></li> <li class="menu-444 "><a class="" title="" href="https://cds.cern.ch/submit?ln=de">Absenden</a></li> <li class="menu-426 "><a class="" href="https://cds.cern.ch/help/?ln=de">Hilfe</a></li> <li class="leaf hassubcdsmenu"> <a hreflang="en" class="header" href="https://cds.cern.ch/youraccount/display?ln=de">Personalisieren</a> <ul class="subsubcdsmenu"><li><a href="https://cds.cern.ch/youralerts/list?ln=de">Ihre Benachrichtigungen</a></li><li><a href="https://cds.cern.ch/yourbaskets/display?ln=de">Ihre Körbe</a></li><li><a href="https://cds.cern.ch/yourcomments?ln=de">Your comments</a></li><li><a href="https://cds.cern.ch/youralerts/display?ln=de">Ihre Suchanfragen</a></li></ul></li> </ul> </div> </div> </div>  <table class="navtrailbox"> <tr> <td class="navtrailboxbody"> <a href="/?ln=de" class="navtrail">Hauptseite</a> > <a class="navtrail" href="/record/2846167">Degradation and Recovery of the LHC RF Cryomodule Performance Using the Helium Processing Technique</a> > HTML MARC </td> </tr> </table> </div> <div class="pagebody"><div class="pagebodystripemiddle"> <pre style="margin: 1em 0px;">002846167 001__ 2846167 002846167 003__ SzGeCERN 002846167 005__ 20230114231744.0 002846167 0247_ $$2DOI$$9JACOW$$a10.18429/JACoW-SRF2021-THPFAV006 002846167 0248_ $$aoai:cds.cern.ch:2846167$$pcerncds:FULLTEXT$$pcerncds:CERN:FULLTEXT$$pcerncds:CERN 002846167 035__ $$9https://inspirehep.net/api/oai2d$$aoai:inspirehep.net:2173931$$d2023-01-13T14:13:08Z$$h2023-01-14T05:00:02Z$$mmarcxml 002846167 035__ $$9Inspire$$a2173931 002846167 041__ $$aeng 002846167 100__ $$aTuraj, Katarzyna$$jJACoW-00094998$$mkatarzyna.turaj@cern.ch$$uCERN 002846167 245__ $$9JACOW$$aDegradation and Recovery of the LHC RF Cryomodule Performance Using the Helium Processing Technique 002846167 260__ $$c2022 002846167 300__ $$a5 p 002846167 520__ $$9JACOW$$aThe LHC RF cryomodule "Asia" suffered an accidental influx of about 0.5 l of tunnel air during the leak checks of the pumping manifolds. The resulting risk of particle contamination was difficult to assess, and could not be excluded with certainty. If one or more cavities were contaminated, a severe impact on beam operations in the LHC machine was to be expected. In order to minimize the risks, the Asia cryomodule has been replaced with a spare unit. Subsequently, the cryomodule was tested in the SM18 test facility without intermediate venting, and showed high levels of radiation due to field emission above 1.8 MV in one of the cavities. The other cavities were less strongly affected, but clear signs of contamination were observed. The helium processing technique was used to improve the performance of the SRF cavity with respect to field emission. This paper will discuss the results of the above-mentioned test. 002846167 540__ $$3publication$$aCC-BY-4.0$$bJACOW$$uhttps://creativecommons.org/licenses/by/4.0 002846167 542__ $$3publication$$g2022 002846167 65017 $$2SzGeCERN$$aAccelerators and Storage Rings 002846167 6531_ $$9author$$acavity 002846167 6531_ $$9author$$acryomodule 002846167 6531_ $$9author$$avacuum 002846167 6531_ $$9author$$aradiation 002846167 6531_ $$9author$$aoperation 002846167 690C_ $$aARTICLE 002846167 690C_ $$aCERN 002846167 693__ $$aCERN LHC 002846167 700__ $$aBrunner, Olivier$$jJACoW-00046019$$molivier.brunner@cern.ch$$uCERN 002846167 700__ $$aButterworth, Andrew$$jJACoW-00001682$$mandrew.butterworth@cern.ch$$uCERN 002846167 700__ $$aGerigk, Frank$$jJACoW-00003184$$mfrank.gerigk@cern.ch$$uCERN 002846167 700__ $$aMaesen, Pierre$$jJACoW-00007023$$mpierre.maesen@cern.ch$$uCERN 002846167 700__ $$aMontesinos, Eric$$jJACoW-00019509$$meric.montesinos@cern.ch$$uCERN 002846167 700__ $$aPeauger, Franck$$jJACoW-00025309$$mfranck.peauger@cea.fr$$uCERN 002846167 700__ $$aTherasse, Mathieu$$jJACoW-00046578$$mmathieu.therasse@cern.ch$$uCERN 002846167 700__ $$aVenturini Delsolaro, Walter$$jJACoW-00003806$$mwalter.venturini@cern.ch$$uCERN 002846167 773__ $$c746-750$$pJACoW SRF$$qSRF2021$$v2021$$wC21-06-28.5$$y2022 002846167 8564_ $$82417878$$s2366661$$uhttps://cds.cern.ch/record/2846167/files/document.pdf$$yFulltext 002846167 960__ $$a13 002846167 962__ $$b2839869$$k746-750$$nonline20210628 002846167 980__ $$aARTICLE 002846167 980__ $$aConferencePaper</pre></div></div> <footer id="footer" class="pagefooter clearfix">  <div class="pagefooterstripeleft"> CERN Document Server :: <a class="footer" href="https://cds.cern.ch/?ln=de">Suchen</a> :: <a class="footer" href="https://cds.cern.ch/submit?ln=de">Absenden</a> :: <a class="footer" href="https://cds.cern.ch/youraccount/display?ln=de">Personalisieren</a> :: <a class="footer" href="https://cds.cern.ch/help/?ln=de">Hilfe</a> :: <a class="footer" href="https://cern.service-now.com/service-portal?id=privacy_policy&se=CDS-Service" target="_blank">Privacy Notice</a> :: <a class="footer" href="https://repository.cern/content-policy" target="_blank">Content Policy</a> :: <a class="footer" href="https://repository.cern/terms" target="_blank">Terms and Conditions</a> <br /> Powered by <a class="footer" href="http://invenio-software.org/">Invenio</a> <br /> Verwaltet von <a class="footer" href="https://cern.service-now.com/service-portal?id=service_element&name=CDS-Service">CDS Service</a> - Need help? 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