Development of a beam position monitor based on Cherenkov diffraction radiation for the AWAKE experiment at CERN
<p>The Plasma Wakefield Experiment (AWAKE) at CERN utilises 400 GeV proton bunches from the Super Proton Synchrotron (SPS) to generate plasma wakefields in a 10 m-long rubidium vapour cell for high-gradient acceleration of 16 MeV electron bunches. The proton and electron bunches propagate clos...
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| Format: | Thesis |
| Language: | English |
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2023
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| _version_ | 1797112249447350272 |
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| author | Pakuza, C |
| author2 | Burrows, P |
| author_facet | Burrows, P Pakuza, C |
| author_sort | Pakuza, C |
| collection | OXFORD |
| description | <p>The Plasma Wakefield Experiment (AWAKE) at CERN utilises 400 GeV proton bunches from the Super Proton Synchrotron (SPS) to generate plasma wakefields in a 10 m-long rubidium vapour cell for high-gradient acceleration of 16 MeV electron bunches. The proton and electron bunches propagate closely in time and space within the common beam-line before the entrance of the plasma cell. The proton bunches possess a bunch charge of 48 nC and a RMS bunch length of 200 − 400 ps , while the electron bunches carry a much lower bunch charge of ∼ 600 pC and have a few ps bunch length. The independent position monitoring of both beam bunches is mission critical to ensure a perfect overlap of their trajectories in the plasma cell. Unfortunately, the current electron beam position monitoring (BPM) system operates at 404 MHz, in a spectral region where the electron signal is completely overshadowed by the proton signal. In order to exclusively measure the electron bunches in the presence of the more-intense proton bunches, a BPM operating at a sufficiently high frequency is required, still within the electron bunch spectrum, but well outside the proton bunch spectrum.</p>
<p>The work detailed in this thesis on the development of a novel type of BPM based on Cherenkov diffraction radiation (ChDR) aims at addressing this problem. ChDR is generated by the surface of a dielectric medium, commonly referred to as a radiator, when a charged particle passes in close proximity under the Cherenkov condition. The thesis provides an overview of the currently employed analytical model describing ChDR, comparing it with numerical simulations. It presents the design process of the ChDR BPM for AWAKE, aided by numerical simulations. Furthermore, it details the design and execution of an RF test-bench characterisation of the ChDR radiator for AWAKE, aiming to bridge the gap between numerical simulations and experimental beam tests. Finally, the thesis reports on the systematic beam studies of the physical ChDR BPM devices, performed at AWAKE and at the CERN Linear Electron Accelerator for Research (CLEAR) test facility, involving both proton and electron beams.</p> |
| first_indexed | 2024-03-07T08:21:31Z |
| format | Thesis |
| id | oxford-uuid:57227483-7806-4b64-bf31-be964b1b72a8 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T08:21:31Z |
| publishDate | 2023 |
| record_format | dspace |
| spelling | oxford-uuid:57227483-7806-4b64-bf31-be964b1b72a82024-02-01T09:07:32ZDevelopment of a beam position monitor based on Cherenkov diffraction radiation for the AWAKE experiment at CERNThesishttp://purl.org/coar/resource_type/c_db06uuid:57227483-7806-4b64-bf31-be964b1b72a8PhysicsParticle acceleratorsEnglishHyrax Deposit2023Pakuza, CBurrows, PMazzoni, SWendt, M<p>The Plasma Wakefield Experiment (AWAKE) at CERN utilises 400 GeV proton bunches from the Super Proton Synchrotron (SPS) to generate plasma wakefields in a 10 m-long rubidium vapour cell for high-gradient acceleration of 16 MeV electron bunches. The proton and electron bunches propagate closely in time and space within the common beam-line before the entrance of the plasma cell. The proton bunches possess a bunch charge of 48 nC and a RMS bunch length of 200 − 400 ps , while the electron bunches carry a much lower bunch charge of ∼ 600 pC and have a few ps bunch length. The independent position monitoring of both beam bunches is mission critical to ensure a perfect overlap of their trajectories in the plasma cell. Unfortunately, the current electron beam position monitoring (BPM) system operates at 404 MHz, in a spectral region where the electron signal is completely overshadowed by the proton signal. In order to exclusively measure the electron bunches in the presence of the more-intense proton bunches, a BPM operating at a sufficiently high frequency is required, still within the electron bunch spectrum, but well outside the proton bunch spectrum.</p> <p>The work detailed in this thesis on the development of a novel type of BPM based on Cherenkov diffraction radiation (ChDR) aims at addressing this problem. ChDR is generated by the surface of a dielectric medium, commonly referred to as a radiator, when a charged particle passes in close proximity under the Cherenkov condition. The thesis provides an overview of the currently employed analytical model describing ChDR, comparing it with numerical simulations. It presents the design process of the ChDR BPM for AWAKE, aided by numerical simulations. Furthermore, it details the design and execution of an RF test-bench characterisation of the ChDR radiator for AWAKE, aiming to bridge the gap between numerical simulations and experimental beam tests. Finally, the thesis reports on the systematic beam studies of the physical ChDR BPM devices, performed at AWAKE and at the CERN Linear Electron Accelerator for Research (CLEAR) test facility, involving both proton and electron beams.</p> |
| spellingShingle | Physics Particle accelerators Pakuza, C Development of a beam position monitor based on Cherenkov diffraction radiation for the AWAKE experiment at CERN |
| title | Development of a beam position monitor based on Cherenkov diffraction radiation for the AWAKE experiment at CERN |
| title_full | Development of a beam position monitor based on Cherenkov diffraction radiation for the AWAKE experiment at CERN |
| title_fullStr | Development of a beam position monitor based on Cherenkov diffraction radiation for the AWAKE experiment at CERN |
| title_full_unstemmed | Development of a beam position monitor based on Cherenkov diffraction radiation for the AWAKE experiment at CERN |
| title_short | Development of a beam position monitor based on Cherenkov diffraction radiation for the AWAKE experiment at CERN |
| title_sort | development of a beam position monitor based on cherenkov diffraction radiation for the awake experiment at cern |
| topic | Physics Particle accelerators |
| work_keys_str_mv | AT pakuzac developmentofabeampositionmonitorbasedoncherenkovdiffractionradiationfortheawakeexperimentatcern |