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Verification by RF measurements of new HOM mitigation scheme developed for future SPS 33-cell accelerating structures

Longitudinal higher-order modes (HOMs) at a frequency of around 630 MHz in the 200 MHz travelling wave RF structures currently limit the beam intensities in the CERN SPS to less than that required by the High Luminosity (HL-) LHC. In the framework of the LHC Injectors Upgrade (LIU) project, the perf...

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Detalles Bibliográficos
Autores principales: Kramer, Patrick, Farricker, Aaron, Vollinger, Christine
Lenguaje:eng
Publicado: 2019
Materias:
Acceso en línea:https://dx.doi.org/10.18429/JACoW-IPAC2019-MOPGW076
http://cds.cern.ch/record/2695081
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author Kramer, Patrick
Farricker, Aaron
Vollinger, Christine
author_facet Kramer, Patrick
Farricker, Aaron
Vollinger, Christine
author_sort Kramer, Patrick
collection CERN
description Longitudinal higher-order modes (HOMs) at a frequency of around 630 MHz in the 200 MHz travelling wave RF structures currently limit the beam intensities in the CERN SPS to less than that required by the High Luminosity (HL-) LHC. In the framework of the LHC Injectors Upgrade (LIU) project, the performance of the already existing HOM damping scheme for these standing wave modes must be improved. This involves improving the existing HOM-couplers as well as the possible use of a new mitigation technique via the insertion of resonant posts in some cells of the multi-cell structures. The development of the new damping scheme has been performed using theoretical analysis of the cavity-coupler interaction in conjunction with full-wave electromagnetic (EM) field simulations. This contribution will show the verification of the improved HOM damping performance by measurements on a single section with 11 cells and on the future 33-cell structures. The parasitic impact of the damping scheme on the travelling wave fundamental passband (FPB) will also be presented.
id oai-inspirehep.net-1743343
institution Organización Europea para la Investigación Nuclear
language eng
publishDate 2019
record_format invenio
spelling oai-inspirehep.net-17433432020-09-28T09:50:08Zdoi:10.18429/JACoW-IPAC2019-MOPGW076http://cds.cern.ch/record/2695081engKramer, PatrickFarricker, AaronVollinger, ChristineVerification by RF measurements of new HOM mitigation scheme developed for future SPS 33-cell accelerating structuresAccelerators and Storage RingsLongitudinal higher-order modes (HOMs) at a frequency of around 630 MHz in the 200 MHz travelling wave RF structures currently limit the beam intensities in the CERN SPS to less than that required by the High Luminosity (HL-) LHC. In the framework of the LHC Injectors Upgrade (LIU) project, the performance of the already existing HOM damping scheme for these standing wave modes must be improved. This involves improving the existing HOM-couplers as well as the possible use of a new mitigation technique via the insertion of resonant posts in some cells of the multi-cell structures. The development of the new damping scheme has been performed using theoretical analysis of the cavity-coupler interaction in conjunction with full-wave electromagnetic (EM) field simulations. This contribution will show the verification of the improved HOM damping performance by measurements on a single section with 11 cells and on the future 33-cell structures. The parasitic impact of the damping scheme on the travelling wave fundamental passband (FPB) will also be presented.CERN-ACC-2019-090oai:inspirehep.net:17433432019
spellingShingle Accelerators and Storage Rings
Kramer, Patrick
Farricker, Aaron
Vollinger, Christine
Verification by RF measurements of new HOM mitigation scheme developed for future SPS 33-cell accelerating structures
title Verification by RF measurements of new HOM mitigation scheme developed for future SPS 33-cell accelerating structures
title_full Verification by RF measurements of new HOM mitigation scheme developed for future SPS 33-cell accelerating structures
title_fullStr Verification by RF measurements of new HOM mitigation scheme developed for future SPS 33-cell accelerating structures
title_full_unstemmed Verification by RF measurements of new HOM mitigation scheme developed for future SPS 33-cell accelerating structures
title_short Verification by RF measurements of new HOM mitigation scheme developed for future SPS 33-cell accelerating structures
title_sort verification by rf measurements of new hom mitigation scheme developed for future sps 33-cell accelerating structures
topic Accelerators and Storage Rings
url https://dx.doi.org/10.18429/JACoW-IPAC2019-MOPGW076
http://cds.cern.ch/record/2695081
work_keys_str_mv AT kramerpatrick verificationbyrfmeasurementsofnewhommitigationschemedevelopedforfuturesps33cellacceleratingstructures
AT farrickeraaron verificationbyrfmeasurementsofnewhommitigationschemedevelopedforfuturesps33cellacceleratingstructures
AT vollingerchristine verificationbyrfmeasurementsofnewhommitigationschemedevelopedforfuturesps33cellacceleratingstructures