{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/19305"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/19305","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Experimental studies of multipass beam breakup and energy recovery using the CEBAF injector linac","abstract":"Beam breakup (BBU) instabilities in superconducting linacs are a significant issue due to the potentially high Q of the cavity higher-order modes (HOMs). The CEBAF accelerator, which employs five pass recirculation through two superconducting linacs to accelerate high CW current (up to 200 $\\mu$A), poses unique instability problems. An experimental investigation of multipass BBU at CEBAF has been completed using a single recirculation through the CEBAF injector linac. This recirculator is calculated to be more sensitive to the instability than the full CEBAF accelerator. Successful recirculation through the injector of a beam with greater than 200 $\\mu$A average current from an injection energy of 5.6 MeV to a final energy of 80.1 MeV indicates that BBU should not be a problem in the full CEBAF accelerator. In addition, we were able recover all the energy from a 30 $\\mu$A 42.8 MeV first pass beam by recirculating it out of phase and decelerating it to a final energy equal to the injection energy (5.6 MeV).","abstract_html":"Beam breakup (BBU) instabilities in superconducting linacs are a significant issue due to the potentially high Q of the cavity higher-order modes (HOMs). The CEBAF accelerator, which employs five pass recirculation through two superconducting linacs to accelerate high CW current (up to 200 <span class=\"etd-inline-math\">&mu;</span>A), poses unique instability problems. An experimental investigation of multipass BBU at CEBAF has been completed using a single recirculation through the CEBAF injector linac. This recirculator is calculated to be more sensitive to the instability than the full CEBAF accelerator. Successful recirculation through the injector of a beam with greater than 200 <span class=\"etd-inline-math\">&mu;</span>A average current from an injection energy of 5.6 MeV to a final energy of 80.1 MeV indicates that BBU should not be a problem in the full CEBAF accelerator. In addition, we were able recover all the energy from a 30 <span class=\"etd-inline-math\">&mu;</span>A 42.8 MeV first pass beam by recirculating it out of phase and decelerating it to a final energy equal to the injection energy (5.6 MeV).","abstract_has_math":true,"creators":["Sereno, Nicholas S.R."],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Cardman, Lawrence S."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T12:03:20Z","date_published":"2011-05-07T12:03:20Z","updated_at":"2026-07-22T22:25:12Z","subjects":["Physics, General"],"languages":["eng"],"rights":["Copyright 1994 Sereno, Nicholas S. 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Successful recirculation through the injector of a beam with greater than 200 $\\mu$A average current from an injection energy of 5.6 MeV to a final energy of 80.1 MeV indicates that BBU should not be a problem in the full CEBAF accelerator. In addition, we were able recover all the energy from a 30 $\\mu$A 42.8 MeV first pass beam by recirculating it out of phase and decelerating it to a final energy equal to the injection energy (5.6 MeV).","Made available in DSpace on 2011-05-07T12:03:20Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9416432.pdf: 6834538 bytes, checksum: 0fb66429b8f9a70b124b26b922357962 (MD5) Previous issue date: 1994","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:36:03Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:14:26-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Experimental studies of multipass beam breakup and energy recovery using the CEBAF injector linac"]}]}],"canonical_facts":{"dc:contributor":["Cardman, Lawrence S."],"dc:creator":["Sereno, Nicholas S.R."],"dc:date":["2011-05-07T12:03:20Z","10000-01-01","1994"],"dc:description":["Beam breakup (BBU) instabilities in superconducting linacs are a significant issue due to the potentially high Q of the cavity higher-order modes (HOMs). The CEBAF accelerator, which employs five pass recirculation through two superconducting linacs to accelerate high CW current (up to 200 $\\mu$A), poses unique instability problems. An experimental investigation of multipass BBU at CEBAF has been completed using a single recirculation through the CEBAF injector linac. This recirculator is calculated to be more sensitive to the instability than the full CEBAF accelerator. Successful recirculation through the injector of a beam with greater than 200 $\\mu$A average current from an injection energy of 5.6 MeV to a final energy of 80.1 MeV indicates that BBU should not be a problem in the full CEBAF accelerator. In addition, we were able recover all the energy from a 30 $\\mu$A 42.8 MeV first pass beam by recirculating it out of phase and decelerating it to a final energy equal to the injection energy (5.6 MeV).","Made available in DSpace on 2011-05-07T12:03:20Z (GMT). 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R."],"dc:subject":["Physics, General"],"dc:title":["Experimental studies of multipass beam breakup and energy recovery using the CEBAF injector linac"],"dc:type":["text"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:12Z"}