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oai:www.ideals.illinois.edu:2142/19305 2023-07-10 col_2142_5131 col_2142_8859 com_2142_5130 com_2142_8858 com_2142_234

Cardman, Lawrence S. Sereno, Nicholas S.R. 2011-05-07T12:03:20Z 2011-05-07T12:03:20Z 10000-01-01 1994 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). 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 AAI9416432 (UMI)AAI9416432 http://hdl.handle.net/2142/19305 eng Copyright 1994 Sereno, Nicholas S. R. Physics, General Experimental studies of multipass beam breakup and energy recovery using the CEBAF injector linac text Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.