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Numerical Simulations for the Beam-Induced Electron Cloud in the LHC Beam Screen

The following work summarises simulation results obtained at CERN for the beam-induced electron cloud and looks at possible cures for the heat load in the LHC beam screen. The synchrotron radiation in the LHC creates a continuous flow of photoelectrons. These electrons are accelerated by the electri...

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Autor principal: Brüning, Oliver Sim
Lenguaje:eng
Publicado: 1998
Materias:
Acceso en línea:http://cds.cern.ch/record/359253
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author Brüning, Oliver Sim
author_facet Brüning, Oliver Sim
author_sort Brüning, Oliver Sim
collection CERN
description The following work summarises simulation results obtained at CERN for the beam-induced electron cloud and looks at possible cures for the heat load in the LHC beam screen. The synchrotron radiation in the LHC creates a continuous flow of photoelectrons. These electrons are accelerated by the electric field of the bunch and hit the vacuum chamber on the opposite side of the beam pipe where they crea te secondary electrons which are again accelerated by the next bunch. For a large secondary emission yield the above mechanism leads to an exponential growth of the electron cloud which is limited by space charge forces. The simulations use a two-dimensional mesh for the space charge calculations and include the effect of image charges on the vacuum chamber wall. Depending on the quantum yield for the production of photoelectrons, the secondary emission yield and the reflectivity, the heat load can vary from 0.1 W/m to more than 15 W/m.
id cern-359253
institution Organización Europea para la Investigación Nuclear
language eng
publishDate 1998
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spelling cern-3592532023-05-31T13:22:18Zhttp://cds.cern.ch/record/359253engBrüning, Oliver SimNumerical Simulations for the Beam-Induced Electron Cloud in the LHC Beam ScreenAccelerators and Storage RingsThe following work summarises simulation results obtained at CERN for the beam-induced electron cloud and looks at possible cures for the heat load in the LHC beam screen. The synchrotron radiation in the LHC creates a continuous flow of photoelectrons. These electrons are accelerated by the electric field of the bunch and hit the vacuum chamber on the opposite side of the beam pipe where they crea te secondary electrons which are again accelerated by the next bunch. For a large secondary emission yield the above mechanism leads to an exponential growth of the electron cloud which is limited by space charge forces. The simulations use a two-dimensional mesh for the space charge calculations and include the effect of image charges on the vacuum chamber wall. Depending on the quantum yield for the production of photoelectrons, the secondary emission yield and the reflectivity, the heat load can vary from 0.1 W/m to more than 15 W/m.LHC-Project-Report-190CERN-LHC-Project-Report-190oai:cds.cern.ch:3592531998-06-03
spellingShingle Accelerators and Storage Rings
Brüning, Oliver Sim
Numerical Simulations for the Beam-Induced Electron Cloud in the LHC Beam Screen
title Numerical Simulations for the Beam-Induced Electron Cloud in the LHC Beam Screen
title_full Numerical Simulations for the Beam-Induced Electron Cloud in the LHC Beam Screen
title_fullStr Numerical Simulations for the Beam-Induced Electron Cloud in the LHC Beam Screen
title_full_unstemmed Numerical Simulations for the Beam-Induced Electron Cloud in the LHC Beam Screen
title_short Numerical Simulations for the Beam-Induced Electron Cloud in the LHC Beam Screen
title_sort numerical simulations for the beam-induced electron cloud in the lhc beam screen
topic Accelerators and Storage Rings
url http://cds.cern.ch/record/359253
work_keys_str_mv AT bruningoliversim numericalsimulationsforthebeaminducedelectroncloudinthelhcbeamscreen