Using surface impedance for calculating wakefields in flat geometry
Abstract
Beginning with Maxwell's equations and assuming only that the wall interaction can be approximated by a surface impedance, we derive formulas for the generalized longitudinal and transverse impedance in flat geometry, from which the wakefields can also be obtained. From the generalized impedances, by taking the proper limits, we obtain the normal longitudinal, dipole, and quad impedances in flat geometry. These equations can be applied to any surface impedance, such as the known dc, ac, and anomalous skin models of wall resistance, a model of wall roughness, or one for a pipe with small, periodic corrugations. We show that, for the particular case of dc wall resistance, the longitudinal impedance obtained here agrees with a known result in the literature, a result that was derived from a very general formula by Henke and Napoly. As an example, we apply our results to representative beam and machine parameters in the undulator region of LCLSII and estimate the impact of the transverse wakes on the machine performance.
 Authors:
 SLAC National Accelerator Lab., Menlo Park, CA (United States)
 Publication Date:
 Research Org.:
 SLAC National Accelerator Lab., Menlo Park, CA (United States)
 Sponsoring Org.:
 USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC22)
 OSTI Identifier:
 1180057
 Alternate Identifier(s):
 OSTI ID: 1168986
 Report Number(s):
 SLACPUB16203
Journal ID: ISSN 10984402; PRABFM
 Grant/Contract Number:
 AC0276SF00515
 Resource Type:
 Journal Article: Published Article
 Journal Name:
 Physical Review Special Topics. Accelerators and Beams
 Additional Journal Information:
 Journal Volume: 18; Journal Issue: 3; Journal ID: ISSN 10984402
 Publisher:
 American Physical Society (APS)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 43 PARTICLE ACCELERATORS; free electron lasers (FELs); flat geometry; longitudinal impedance; transverse impedance; particle trajectories
Citation Formats
Bane, Karl, and Stupakov, Gennady. Using surface impedance for calculating wakefields in flat geometry. United States: N. p., 2015.
Web. doi:10.1103/PhysRevSTAB.18.034401.
Bane, Karl, & Stupakov, Gennady. Using surface impedance for calculating wakefields in flat geometry. United States. doi:10.1103/PhysRevSTAB.18.034401.
Bane, Karl, and Stupakov, Gennady. 2015.
"Using surface impedance for calculating wakefields in flat geometry". United States.
doi:10.1103/PhysRevSTAB.18.034401.
@article{osti_1180057,
title = {Using surface impedance for calculating wakefields in flat geometry},
author = {Bane, Karl and Stupakov, Gennady},
abstractNote = {Beginning with Maxwell's equations and assuming only that the wall interaction can be approximated by a surface impedance, we derive formulas for the generalized longitudinal and transverse impedance in flat geometry, from which the wakefields can also be obtained. From the generalized impedances, by taking the proper limits, we obtain the normal longitudinal, dipole, and quad impedances in flat geometry. These equations can be applied to any surface impedance, such as the known dc, ac, and anomalous skin models of wall resistance, a model of wall roughness, or one for a pipe with small, periodic corrugations. We show that, for the particular case of dc wall resistance, the longitudinal impedance obtained here agrees with a known result in the literature, a result that was derived from a very general formula by Henke and Napoly. As an example, we apply our results to representative beam and machine parameters in the undulator region of LCLSII and estimate the impact of the transverse wakes on the machine performance.},
doi = {10.1103/PhysRevSTAB.18.034401},
journal = {Physical Review Special Topics. Accelerators and Beams},
number = 3,
volume = 18,
place = {United States},
year = 2015,
month = 3
}
Web of Science

Beginning with Maxwell's equations and assuming only that the wall interaction can be approximated by a surface impedance, we derive formulas for the generalized longitudinal and transverse impedance in flat geometry, from which the wakefields can also be obtained. From the generalized impedances, by taking the proper limits, we obtain the normal longitudinal, dipole, and quad impedances in flat geometry. These equations can be applied to any surface impedance, such as the known dc, ac, and anomalous skin models of wall resistance, a model of wall roughness, or one for a pipe with small, periodic corrugations. We show that, formore »Cited by 10

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