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The CERN Linear Electron Accelerator for Research (CLEAR) is an irradiation facility that produces 200 MeV beams of electrons with parameters tuned to the needs of users. One of the most commonly requested beam parameters is for bunch lengths of less than 1 ps, which was not previously possible for high-charge bunches. In this thesis, the ability to compress high-charge bunches to sub-ps bunch lengths, using the velocity bunching technique, is shown in simulation. The simulations are then verified with experimental measurements taken at CLEAR. The ability to reduce the emittance of the beam during compression is also presented. Potential upgrades to the CLEAR facility are proposed, namely a new laser system and the installation of an additional klystron. The benefits of these upgrades are explored in simulation, demonstrating that they would allow the production of shorter bunches, with lower energy spread, and lower emittance. It is shown that by using a modified version of the CLEAR photoinjector it is possible to produce bunches with a uniform transverse profile using a simple Gaussian laser with a 1 ps pulse length. A compact irradiation facility was proposed consisting of the CLEAR photoinjector, an X-band linac using cavities similar to those developed for the Compact Linear Collider, and a quadrupole matching section. It was shown that such a facility could produce beams of different sizes with uniform beam profiles. The stability of such a facility was investigated, demonstrating that beam jitters do not significantly reduce beam uniformity. Dyks, Luke Aidan" /> <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"/>  <meta content="Studies for Upgrading and Optimising the CLEAR Beamline, and Generating Uniform Electron-Beam Profiles for Irradiation Experiments" name="citation_title" /> <meta content="Dyks, Luke Aidan" name="citation_author" /> <meta name="citation_online_date" content="2023/06/27"> <meta content="CERN-THESIS-2022-365" name="citation_technical_report_number" /> <meta content="Oxford U." name="citation_dissertation_institution" /> <meta name="citation_pdf_url" content="https://cds.cern.ch/record/2863106/files/CERN-THESIS-2022-365.pdf" />  <meta content="Studies for Upgrading and Optimising the CLEAR Beamline, and Generating Uniform Electron-Beam Profiles for Irradiation Experiments" property="og:title" /> <meta content="website" property="og:type" /> <meta content="https://cds.cern.ch/record/2863106" property="og:url" /> <meta content="CERN Document Server" property="og:site_name" /> <meta content="Irradiation facilities around the world are used to investigate the effect of high-energy particle beams on electronics, to study the makeup of historical objects and art, and for medical applications, notably radiotherapy. The CERN Linear Electron Accelerator for Research (CLEAR) is an irradiation facility that produces 200 MeV beams of electrons with parameters tuned to the needs of users. One of the most commonly requested beam parameters is for bunch lengths of less than 1 ps, which was not previously possible for high-charge bunches. In this thesis, the ability to compress high-charge bunches to sub-ps bunch lengths, using the velocity bunching technique, is shown in simulation. The simulations are then verified with experimental measurements taken at CLEAR. The ability to reduce the emittance of the beam during compression is also presented. Potential upgrades to the CLEAR facility are proposed, namely a new laser system and the installation of an additional klystron. The benefits of these upgrades are explored in simulation, demonstrating that they would allow the production of shorter bunches, with lower energy spread, and lower emittance. It is shown that by using a modified version of the CLEAR photoinjector it is possible to produce bunches with a uniform transverse profile using a simple Gaussian laser with a 1 ps pulse length. A compact irradiation facility was proposed consisting of the CLEAR photoinjector, an X-band linac using cavities similar to those developed for the Compact Linear Collider, and a quadrupole matching section. It was shown that such a facility could produce beams of different sizes with uniform beam profiles. The stability of such a facility was investigated, demonstrating that beam jitters do not significantly reduce beam uniformity." property="og:description" />  <meta content="summary" name="twitter:card" /> <style></style> </head> <body class="CERN32Document32Server 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=https%3A//cds.cern.ch/record/2863106/export/hm%3Fln%3Den" 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=en">Search</a></li> <li class="menu-444 "><a class="" title="" href="https://cds.cern.ch/submit?ln=en">Submit</a></li> <li class="menu-426 "><a class="" href="https://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 class="navtrail" href="/record/2863106">Studies for Upgrading and Optimising the CLEAR Beamline, and Generating Uniform Electron-Beam Profiles for Irradiation Experiments</a> > HTML MARC </td> </tr> </table> </div> <div class="pagebody"><div class="pagebodystripemiddle"> <pre style="margin: 1em 0px;">002863106 001__ 2863106 002863106 005__ 20240221153332.0 002863106 0248_ $$aoai:cds.cern.ch:2863106$$pcerncds:FULLTEXT$$pcerncds:THESES$$pcerncds:CERN:FULLTEXT$$pINIS$$pcerncds:CERN 002863106 037__ $$aCERN-THESIS-2022-365 002863106 035__ $$9Inspire$$a2675454 002863106 041__ $$aeng 002863106 100__ $$0AUTHOR|(CDS)2666981$$0AUTHOR|(SzGeCERN)829832$$aDyks, Luke Aidan$$mluke.dyks@cern.ch$$uOxford U. 002863106 245__ $$aStudies for Upgrading and Optimising the CLEAR Beamline, and Generating Uniform Electron-Beam Profiles for Irradiation Experiments 002863106 300__ $$a170 p 002863106 500__ $$aPresented 19 Aug 2022 002863106 502__ $$aPhD$$bOxford U.$$c2022 002863106 520__ $$aIrradiation facilities around the world are used to investigate the effect of high-energy particle beams on electronics, to study the makeup of historical objects and art, and for medical applications, notably radiotherapy. The CERN Linear Electron Accelerator for Research (CLEAR) is an irradiation facility that produces 200 MeV beams of electrons with parameters tuned to the needs of users. One of the most commonly requested beam parameters is for bunch lengths of less than 1 ps, which was not previously possible for high-charge bunches. In this thesis, the ability to compress high-charge bunches to sub-ps bunch lengths, using the velocity bunching technique, is shown in simulation. The simulations are then verified with experimental measurements taken at CLEAR. The ability to reduce the emittance of the beam during compression is also presented. Potential upgrades to the CLEAR facility are proposed, namely a new laser system and the installation of an additional klystron. The benefits of these upgrades are explored in simulation, demonstrating that they would allow the production of shorter bunches, with lower energy spread, and lower emittance. It is shown that by using a modified version of the CLEAR photoinjector it is possible to produce bunches with a uniform transverse profile using a simple Gaussian laser with a 1 ps pulse length. A compact irradiation facility was proposed consisting of the CLEAR photoinjector, an X-band linac using cavities similar to those developed for the Compact Linear Collider, and a quadrupole matching section. It was shown that such a facility could produce beams of different sizes with uniform beam profiles. The stability of such a facility was investigated, demonstrating that beam jitters do not significantly reduce beam uniformity. 002863106 536__ $$aCERN Doctoral Student Program 002863106 595__ $$aCERN EDS 002863106 65017 $$2SzGeCERN$$aAccelerators and Storage Rings 002863106 690C_ $$aCERN 002863106 690C_ $$aTHESIS 002863106 693__ $$aCERN Linac$$eNot applicable 002863106 693__ $$aCLIC$$eNot applicable 002863106 701__ $$aCorsini, Roberto$$edir.$$uCERN 002863106 701__ $$aBurrows, Philip$$edir.$$uOxford U. 002863106 710__ $$5BE 002863106 859__ $$fsylvia.dubourg@cern.ch 002863106 8564_ $$82460708$$s15972843$$uhttps://cds.cern.ch/record/2863106/files/CERN-THESIS-2022-365.pdf 002863106 916__ $$sn$$w202326$$ya2023 002863106 963__ $$aPUBLIC 002863106 960__ $$a14 002863106 980__ $$aTHESIS</pre></div></div> <footer id="footer" class="pagefooter clearfix">  <div class="pagefooterstripeleft"> CERN Document Server :: <a class="footer" href="https://cds.cern.ch/?ln=en">Search</a> :: <a class="footer" href="https://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="https://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? 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