CINXE.COM

<!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="en" xml:lang="en" xmlns:og="http://ogp.me/ns#" xmlns:fb="http://ogp.me/ns/fb#"> <head> <title>Performance Test of a Triple GEM Detector at CERN n_TOF Facility - 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/1496197" /> <link rel="alternate" hreflang="el" href="http://cds.cern.ch/record/1496197?ln=el" /> <link rel="alternate" hreflang="fr" href="http://cds.cern.ch/record/1496197?ln=fr" /> <link rel="alternate" hreflang="bg" href="http://cds.cern.ch/record/1496197?ln=bg" /> <link rel="alternate" hreflang="zh-TW" href="http://cds.cern.ch/record/1496197?ln=zh_TW" /> <link rel="alternate" hreflang="pt" href="http://cds.cern.ch/record/1496197?ln=pt" /> <link rel="alternate" hreflang="no" href="http://cds.cern.ch/record/1496197?ln=no" /> <link rel="alternate" hreflang="hr" href="http://cds.cern.ch/record/1496197?ln=hr" /> <link rel="alternate" hreflang="ca" href="http://cds.cern.ch/record/1496197?ln=ca" /> <link rel="alternate" hreflang="de" href="http://cds.cern.ch/record/1496197?ln=de" /> <link rel="alternate" hreflang="it" href="http://cds.cern.ch/record/1496197?ln=it" /> <link rel="alternate" hreflang="zh-CN" href="http://cds.cern.ch/record/1496197?ln=zh_CN" /> <link rel="alternate" hreflang="sv" href="http://cds.cern.ch/record/1496197?ln=sv" /> <link rel="alternate" hreflang="sk" href="http://cds.cern.ch/record/1496197?ln=sk" /> <link rel="alternate" hreflang="en" href="http://cds.cern.ch/record/1496197?ln=en" /> <link rel="alternate" hreflang="pl" href="http://cds.cern.ch/record/1496197?ln=pl" /> <link rel="alternate" hreflang="ru" href="http://cds.cern.ch/record/1496197?ln=ru" /> <link rel="alternate" hreflang="ka" href="http://cds.cern.ch/record/1496197?ln=ka" /> <link rel="alternate" hreflang="ja" href="http://cds.cern.ch/record/1496197?ln=ja" /> <link rel="alternate" hreflang="es" href="http://cds.cern.ch/record/1496197?ln=es" /> <link rel="alternate" type="application/rss+xml" title="CERN Document Server RSS" href="/rss?ln=en" /> <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="en" /> <meta name="description" content="The application of a triple GEM (Gas Electron Multiplier) for neutron detection was tested at the n_TOF facility at CERN. n_TOF allows the neutron energy distribution to be measured via a ~185 m time of flight path. A 20 GeV/c proton beam hits a lead target generating a neutron spectrum ranging from thermal energies to the GeV region. Due to their long flight path and short proton pulse, the neutron arrival times at the experimental area define their energy (1). A triple GEM detector with a 60 μm Polyethylene (PE) neutron converter and 40 μm of Aluminium, filled with an Ar-CO2 70-30% mixture, was installed a few meters downstream of the experimental area, just in front of the beam dump. The measurements were purely parasitic; they were conducted in parallel and without interfering with the official n_TOF scientific program. Using the n_TOF trigger it is possible to synchronize the GEM data acquisition in order to select a given neutron energy window and measure the detector efficiency as a function of neutron energy. Changing the detector gain, it is possible to perform these measurements with a low gamma-background level. Thanks to the pixelated read-out the neutron beam spot and the efficiency of the detector have been measured. Claps, Gerardo; Croci, Gabriele; Murtas, Fabrizio; Pietropaolo, Antonino; Puddu, Silvia; Severino, Clizia Tecla; Silari, Marco" /> <meta name="keywords" content="GEM, n_TOF, fast neutrons detection" /> <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"/> <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="Performance Test of a Triple GEM Detector at CERN n_TOF Facility" name="citation_title" /> <meta content="Claps, Gerardo" name="citation_author" /> <meta content="Croci, Gabriele" name="citation_author" /> <meta content="Pietropaolo, Antonino" name="citation_author" /> <meta content="Silari, Marco" name="citation_author" /> <meta content="Murtas, Fabrizio" name="citation_author" /> <meta content="Puddu, Silvia" name="citation_author" /> <meta content="Severino, Clizia Tecla" name="citation_author" /> <meta content="2012/10/31" name="citation_publication_date" /> <meta name="citation_online_date" content="2012/11/27"> <meta content="ARDENT-CONF-2012-001" name="citation_technical_report_number" /> <meta name="citation_pdf_url" content="http://cds.cern.ch/record/1496197/files/ARDENT-CONF-2012-001.pdf" />  <meta content="Performance Test of a Triple GEM Detector at CERN n_TOF Facility" property="og:title" /> <meta content="website" property="og:type" /> <meta content="website" property="og:type" /> <meta content="website" property="og:type" /> <meta content="http://cds.cern.ch/record/1496197" property="og:url" /> <meta name="twitter:image" content="http://cds.cern.ch/record/1496197/files/ARDENT-CONF-2012-001.gif?subformat=icon" /> <meta property="og:image" content="http://cds.cern.ch/record/1496197/files/ARDENT-CONF-2012-001.gif?subformat=icon" /> <meta property="og:image:secure_url" content="https://cds.cern.ch/record/1496197/files/ARDENT-CONF-2012-001.gif?subformat=icon" /> <meta property="og:image" content="http://cds.cern.ch/record/1496197/files/ARDENT-CONF-2012-001.gif?subformat=icon" /> <meta property="og:image:secure_url" content="https://cds.cern.ch/record/1496197/files/ARDENT-CONF-2012-001.gif?subformat=icon" /> <meta content="CERN Document Server" property="og:site_name" /> <meta content="The application of a triple GEM (Gas Electron Multiplier) for neutron detection was tested at the n_TOF facility at CERN. n_TOF allows the neutron energy distribution to be measured via a ~185 m time of flight path. A 20 GeV/c proton beam hits a lead target generating a neutron spectrum ranging from thermal energies to the GeV region. Due to their long flight path and short proton pulse, the neutron arrival times at the experimental area define their energy (1). A triple GEM detector with a 60 μm Polyethylene (PE) neutron converter and 40 μm of Aluminium, filled with an Ar-CO2 70-30% mixture, was installed a few meters downstream of the experimental area, just in front of the beam dump. The measurements were purely parasitic; they were conducted in parallel and without interfering with the official n_TOF scientific program. Using the n_TOF trigger it is possible to synchronize the GEM data acquisition in order to select a given neutron energy window and measure the detector efficiency as a function of neutron energy. Changing the detector gain, it is possible to perform these measurements with a low gamma-background level. Thanks to the pixelated read-out the neutron beam spot and the efficiency of the detector have been measured." property="og:description" />  <meta content="summary" name="twitter:card" /> <meta content="summary" name="twitter:card" /> <style></style> </head> <body class="n_TOF32INTC32Public32Documents search" lang="en">  <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=en&referer=http%3A//cds.cern.ch/record/1496197" 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=en">Search</a></li> <li class="menu-444 "><a class="" title="" href="http://cds.cern.ch/submit?ln=en">Submit</a></li> <li class="menu-426 "><a class="" href="http://cds.cern.ch/help/?ln=en">Help</a></li> <li class="leaf hassubcdsmenu"> <a hreflang="en" class="header" href="https://cds.cern.ch/youraccount/display?ln=en">Personalize</a> <ul class="subsubcdsmenu"><li><a href="https://cds.cern.ch/youralerts/list?ln=en">Your alerts</a></li><li><a href="https://cds.cern.ch/yourbaskets/display?ln=en">Your baskets</a></li><li><a href="https://cds.cern.ch/yourcomments?ln=en">Your comments</a></li><li><a href="https://cds.cern.ch/youralerts/display?ln=en">Your searches</a></li></ul></li> </ul> </div> </div> </div>  <table class="navtrailbox"> <tr> <td class="navtrailboxbody"> <a href="/?ln=en" class="navtrail">Home</a> > <a href="/collection/CERN%20Experiments?ln=en" class="navtrail">CERN Experiments</a> > <a href="/collection/PS%20Experiments?ln=en" class="navtrail">PS Experiments</a> > <a href="/collection/n_TOF?ln=en" class="navtrail">n_TOF</a> > <a href="/collection/n_TOF%20INTC%20Public%20Documents?ln=en" class="navtrail">n_TOF INTC Public Documents</a> > Performance Test of a Triple GEM Detector at CERN n_TOF Facility </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/1496197/?ln=en">Information </a></li><li class=""><a href="/record/1496197/comments?ln=en">Discussion (0) </a></li><li class=""><a href="/record/1496197/files?ln=en">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="1496197"></abbr>  <link href="/img/download_and_embed_buttons.css" rel="stylesheet" type="text/css" /> <style type="text/css">  .video_talk_wrapper{ max-width: 640px; min-height: 360px; } </style> <table class="formatRecordTableFullWidth"> <tr> <td class="formatRecordHeader" style="background-image: url('/img/journals.jpg');" colspan="2">  Preprint </td> </tr> <tr><td class="formatRecordLabel"> Report number </td><td style="padding-left:5px;">ARDENT-CONF-2012-001</td></tr> <tr><td class="formatRecordLabel"> Title </td><td style="padding-left:5px;"><b>Performance Test of a Triple GEM Detector at CERN n_TOF Facility</b></td></tr> <style> .video_control_container, #video_controlbutton { display: none; }#video_detailbox_download {display: none;}#video_detailbox_embed {display: none;}</style> <div class="video_control_container"> <div style="box-sizing: inherit;position: relative;min-height: 1em;margin: 1em 0;background: #f8f8f9;padding: 1em 1.5em;line-height: 1.4285em;transition: opacity .1s ease,color .1s ease,background .1s ease,box-shadow .1s ease,-webkit-box-shadow .1s ease;border-radius: .28571429rem;font-size: 1.1em;margin-top: 0;margin-bottom: 6px;background-color: #f8ffff;color: #276f86;box-shadow: 0 0 0 1px #a9d5de inset,0 0 0 0 transparent;"> <i class="fa fa-info"></i><span style="padding-left: 9px;">If you experience any problem watching the video, click the download button below</span> </div> <a id="video_controlbutton_download" rel="download_button" class="video_controlbutton" href="#">Download</a> <a id="video_controlbutton_embed" class="video_controlbutton" href="#">Embed</a> </div> <div id="video_detailbox_download" style="margin:10px"> </div> <div id="video_detailbox_embed" style="margin:10px"> </div> <tr><td class="formatRecordLabel"> <span style="white-space:nowrap;">Author(s)</span> </td><td style="padding-left:5px;"><a href="http://cds.cern.ch/search?f=author&p=Claps%2C%20Gerardo&ln=en">Claps, Gerardo</a> (INFN-LNF) ; <a href="http://cds.cern.ch/search?f=author&p=Croci%2C%20Gabriele&ln=en">Croci, Gabriele</a> (IFP, Milan) ; <a href="http://cds.cern.ch/search?f=author&p=Murtas%2C%20Fabrizio&ln=en">Murtas, Fabrizio</a> (CERN ; Frascati) ; <a href="http://cds.cern.ch/search?f=author&p=Pietropaolo%2C%20Antonino&ln=en">Pietropaolo, Antonino</a> (IFP, Milan) ; <a href="http://cds.cern.ch/search?f=author&p=Puddu%2C%20Silvia&ln=en">Puddu, Silvia</a> (CERN ; Bern U., LHEP) ; <a href="http://cds.cern.ch/search?f=author&p=Severino%2C%20Clizia%20Tecla&ln=en">Severino, Clizia Tecla</a> (CERN ; Bern U., LHEP) ; <a href="http://cds.cern.ch/search?f=author&p=Silari%2C%20Marco&ln=en">Silari, Marco</a> (CERN)</td></tr> <tr><td class="formatRecordLabel"> Publication </td><td style="padding-left:5px;">2012</td></tr>  <script type="text/javascript"> /* * Changes the Imprint title to Date - Duration as requested by RQF0820114 * This is a hack not to touch the general imprint format element */ $(document).ready(function() { var collections = 'PREPRINT ; ConferencePaper'; if (collections.indexOf('E-LEARNING') > -1) { $('.cern-imprint-label').text('Date - Duration'); } }) </script> <tr><td class="formatRecordLabel cern-imprint-label"> Imprint </td><td style="padding-left:5px;">2012-10-31</td></tr>  <tr><td class="formatRecordLabel"> Presented at </td><td style="padding-left:5px;"><a href="http://cds.cern.ch/record/1421982">2012 IEEE Nuclear Science Symposium and Medical Imaging Conference</a>, Anaheim, California, USA, 29 Oct - 3 Nov 2012</td></tr> <tr><td class="formatRecordLabel"> Subject category </td><td style="padding-left:5px;">Detectors and Experimental Techniques</td></tr> <tr><td class="formatRecordLabel"> ARDENT category </td><td style="padding-left:5px;">GEM</td></tr> <tr><td class="formatRecordLabel"> Accelerator/Facility, Experiment </td><td style="padding-left:5px;"><a href="http://cds.cern.ch/search?p=CERN%20PS&f=693__a">CERN PS</a> ; <a href="http://cds.cern.ch/search?p=nTOF&f=693__e">nTOF</a></td></tr> <tr><td class="formatRecordLabel"> Keywords </td><td style="padding-left:5px;"><a href="http://cds.cern.ch/search?f=keyword&p=GEM&ln=en">GEM</a> ; <a href="http://cds.cern.ch/search?f=keyword&p=n_TOF&ln=en">n_TOF</a> ; <a href="http://cds.cern.ch/search?f=keyword&p=fast%20neutrons%20detection&ln=en">fast neutrons detection</a></td></tr> <tr><td class="formatRecordLabel"> Abstract </td><td style="padding-left:5px;">The application of a triple GEM (Gas Electron Multiplier) for neutron detection was tested at the n_TOF facility at CERN. n_TOF allows the neutron energy distribution to be measured via a  185 m time of flight path. A 20 GeV/c proton beam hits a lead target generating a neutron spectrum ranging from thermal energies to the GeV region. Due to their long flight path and short proton pulse, the neutron arrival times at the experimental area define their energy (1). A triple GEM detector with a 60 μm Polyethylene (PE) neutron converter and 40 μm of Aluminium, filled with an Ar-CO2 70-30% mixture, was installed a few meters downstream of the experimental area, just in front of the beam dump. The measurements were purely parasitic; they were conducted in parallel and without interfering with the official n_TOF scientific program. Using the n_TOF trigger it is possible to synchronize the GEM data acquisition in order to select a given neutron energy window and measure the detector efficiency as a function of neutron energy. Changing the detector gain, it is possible to perform these measurements with a low gamma-background level. Thanks to the pixelated read-out the neutron beam spot and the efficiency of the detector have been measured.</td></tr> <tr><td class="formatRecordLabel"> Submitted by </td><td style="padding-left:5px;"><a href="mailto:silvia.puddu@cern.ch">silvia.puddu@cern.ch</a></td></tr> </table> <br/><div><div style="clear: both;"> </div></div> <script type="text/javascript"> // Initially hide: $(".longCaption").hide(); // Allow to toggle visibility: $(".toggleLongCaption").toggle(function(){ $(this).siblings(".longCaption").show('fast'); var thisElem = $(this); thisElem.text(thisElem.text() === "more" ? "less" : "more"); },function(){ $(this).siblings(".longCaption").hide('fast'); var thisElem = $(this); thisElem.text(thisElem.text() === "more" ? "less" : "more"); }); </script> <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"> Record created 2012-11-27, last modified 2014-11-06</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=en&p=recid%3A1496197&rm=wrd" class="moreinfo">Similar records</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:</small> <br /><a href="/record/1496197/files/ARDENT-CONF-2012-001.pdf"><img style="border:none" src="/img/file-icon-text-34x48.gif" alt="Download fulltext" /><br />PDF</a><br /></div> </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=en&recid=1496197">Add to personal basket</a></li> <li>Export as <a style="text-decoration:underline;font-weight:normal" href="/record/1496197/export/hx?ln=en">BibTeX</a>, <a style="text-decoration:underline;font-weight:normal" href="/record/1496197/export/hm?ln=en">MARC</a>, <a style="text-decoration:underline;font-weight:normal" href="/record/1496197/export/xm?ln=en">MARCXML</a>, <a style="text-decoration:underline;font-weight:normal" href="/record/1496197/export/xd?ln=en">DC</a>, <a style="text-decoration:underline;font-weight:normal" href="/record/1496197/export/xe?ln=en">EndNote</a>,  <a style="text-decoration:underline;font-weight:normal" href="/record/1496197/export/xn?ln=en">NLM</a>, <a style="text-decoration:underline;font-weight:normal" href="/record/1496197/export/xw?ln=en">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', 'http://cds.cern.ch/img/sciencewise.png', 'en', 'bookmark', 'http://sciencewise.info/bookmarks/cds:1496197/add'); $('#bookmark_sciencewise').bookmark({sites: ['sciencewise']}); $('#bookmark').bookmark({ sites: ['facebook', 'twitter', 'linkedin', 'google_plusone'], icons: '/img/bookmarks.png', url: 'http://cds.cern.ch/record/1496197', addEmail: true, title: "Performance Test of a Triple GEM Detector at CERN n_TOF Facility", description: "The application of a triple GEM (Gas Electron Multiplier) for neutron detection was tested at the n_TOF facility at CERN. n_TOF allows the neutron energy distribution to be measured via a ~185 m time of flight path. A 20 GeV/c proton beam hits a lead target generating a neutron spectrum ranging from thermal energies to the GeV region. Due to their long flight path and short proton pulse, the neutron arrival times at the experimental area define their energy (1). A triple GEM detector with a 60 \u03bcm Polyethylene (PE) neutron converter and 40 \u03bcm of Aluminium, filled with an Ar-CO2 70-30% mixture, was installed a few meters downstream of the experimental area, just in front of the beam dump. The measurements were purely parasitic; they were conducted in parallel and without interfering with the official n_TOF scientific program. Using the n_TOF trigger it is possible to synchronize the GEM data acquisition in order to select a given neutron energy window and measure the detector efficiency as a function of neutron energy. Changing the detector gain, it is possible to perform these measurements with a low gamma-background level. Thanks to the pixelated read-out the neutron beam spot and the efficiency of the detector have been measured." }); // ]]> </script>  </div> </div> <div style="clear:both;margin-bottom: 0;"></div> </div> <div class="bottom-left"></div><div class="bottom-right"></div> </div> </div></div> <footer id="footer" class="pagefooter clearfix">  <div class="pagefooterstripeleft"> CERN Document Server :: <a class="footer" href="http://cds.cern.ch/?ln=en">Search</a> :: <a class="footer" href="http://cds.cern.ch/submit?ln=en">Submit</a> :: <a class="footer" href="https://cds.cern.ch/youraccount/display?ln=en">Personalize</a> :: <a class="footer" href="http://cds.cern.ch/help/?ln=en">Help</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 /> Maintained by <a class="footer" href="https://cern.service-now.com/service-portal?id=service_element&name=CDS-Service">CDS Service</a> - Need help? Contact <a href="https://cern.service-now.com/service-portal?id=service_element&name=CDS-Service">CDS Support</a>. <br /> </div> <div class="pagefooterstriperight"> <div class="cern-logo"> <a id="logo" href="http://cern.ch" title="CERN" rel="CERN" ><img src="http://cds.cern.ch/img/cern_theme/img/cern-logo-large.png" alt="CERN" /></a> </div> <div class="cern-languagebox"> This site is also available in the following languages:<br /><a href="/record/1496197?ln=bg" class="langinfo">Български</a>  <a href="/record/1496197?ln=ca" class="langinfo">Català</a>  <a href="/record/1496197?ln=de" class="langinfo">Deutsch</a>  <a href="/record/1496197?ln=el" class="langinfo">Ελληνικά</a>  <span class="langinfo">English</span>  <a href="/record/1496197?ln=es" class="langinfo">Español</a>  <a href="/record/1496197?ln=fr" class="langinfo">Français</a>  <a href="/record/1496197?ln=hr" class="langinfo">Hrvatski</a>  <a href="/record/1496197?ln=it" class="langinfo">Italiano</a>  <a href="/record/1496197?ln=ja" class="langinfo">日本語</a>  <a href="/record/1496197?ln=ka" class="langinfo">ქართული</a>  <a href="/record/1496197?ln=no" class="langinfo">Norsk/Bokmål</a>  <a href="/record/1496197?ln=pl" class="langinfo">Polski</a>  <a href="/record/1496197?ln=pt" class="langinfo">Português</a>  <a href="/record/1496197?ln=ru" class="langinfo">Русский</a>  <a href="/record/1496197?ln=sk" class="langinfo">Slovensky</a>  <a href="/record/1496197?ln=sv" class="langinfo">Svenska</a>  <a href="/record/1496197?ln=zh_CN" class="langinfo">中文(简)</a>  <a href="/record/1496197?ln=zh_TW" class="langinfo">中文(繁)</a> </div> </div>  </footer> <script type="text/javascript"> var SyndeticsBookCovers = (function() { var SMALL_SIZE = "sc.gif", MEDIUM_SIZE = "mc.gif", RAW_URL = "https://secure.syndetics.com/index.aspx?isbn=THEISBN/THESIZE&client=cernlibrary"; replaceCover = function(imgElement, isbns, hdFormat) { var img = new Image(), size = hdFormat ? MEDIUM_SIZE : SMALL_SIZE; var _isbns = isbns.sort(function(a, b) { // sort from shortest to longest ISBN (more modern) return a.length > b.length ? 1 : -1; }); function next() { var isbn = _isbns.pop(); if (isbn) { var url = RAW_URL.replace("THEISBN", isbn).replace("THESIZE", size); img.src = url; } } function done() { imgElement.src = img.src; } img.onload = function() { if (this.width > 1) { done(); } else { next(); } }; next(); }; return { replaceCover: replaceCover }; })(); $(document).ready(function() { // get book covers $("img.book-cover").each(function() { var $this = $(this), strIsbns = $this.data("isbns") || "", isbnsArray = String(strIsbns).split(","), hdFormat = $this.hasClass("hd"); SyndeticsBookCovers.replaceCover(this, isbnsArray, hdFormat); }); // WebNews tooltips $.ajax({ url: "/news/tooltips", success: function(data) { create_tooltips(data); }, dataType: "json", cache: false }); }); </script>  <script src="//cds.cern.ch/js/feedback.js"></script>   <script> var _paq = window._paq = window._paq || []; /* tracker methods like "setCustomDimension" should be called before "trackPageView" */ _paq.push(['trackPageView']); _paq.push(['enableLinkTracking']); (function() { var u="https://webanalytics.web.cern.ch/"; _paq.push(['setTrackerUrl', u+'matomo.php']); _paq.push(['setSiteId', '756']); var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0]; g.async=true; g.src=u+'matomo.js'; s.parentNode.insertBefore(g,s); })(); </script>  </body> </html>