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Pragmatic method of deducing a wake function for a general 3D structure

Skripka, Galina LU and Nagaoka, Ryutaro (2015) In Physical Review Special Topics - Accelerators and Beams
Abstract
We present a practical and self-consistent approach to obtaining a wake function to be used in beam instability simulations from a numerical wake potential computed with an electromagnetic (EM) field solver for a finite length test bunch. The wake potential is processed to a numerical impedance by Fourier transforming (FT) it to the frequency domain and deconvoluting the bunch spectrum. We then decompose it into a set of well-known analytical functions that satisfy the causality and Maxwell’s equations, eliminating the unphysical artifacts possibly contained in numerical solutions. Additional inverse FT of the decomposed impedance function into time domain allows retrieving an effective wake function. Relatively long bunches can be used... (More)
We present a practical and self-consistent approach to obtaining a wake function to be used in beam instability simulations from a numerical wake potential computed with an electromagnetic (EM) field solver for a finite length test bunch. The wake potential is processed to a numerical impedance by Fourier transforming (FT) it to the frequency domain and deconvoluting the bunch spectrum. We then decompose it into a set of well-known analytical functions that satisfy the causality and Maxwell’s equations, eliminating the unphysical artifacts possibly contained in numerical solutions. Additional inverse FT of the decomposed impedance function into time domain allows retrieving an effective wake function. Relatively long bunches can be used for the numerical wake potential calculations, significantly reducing the computation time. We show that the method can be applied to a general 3D structure, which opens up the possibility of finding effective wake functions of complicated realistic vacuum chambers. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
submitted
subject
keywords
wakefield, impedance, wake potential
in
Physical Review Special Topics - Accelerators and Beams
publisher
American Physical Society
ISSN
1098-4402
language
English
LU publication?
yes
id
a0635ae8-6c8d-4d23-9d77-ec8474ead72b (old id 8165717)
date added to LUP
2015-11-11 10:02:29
date last changed
2016-11-18 13:57:02
@article{a0635ae8-6c8d-4d23-9d77-ec8474ead72b,
  abstract     = {We present a practical and self-consistent approach to obtaining a wake function to be used in beam instability simulations from a numerical wake potential computed with an electromagnetic (EM) field solver for a finite length test bunch. The wake potential is processed to a numerical impedance by Fourier transforming (FT) it to the frequency domain and deconvoluting the bunch spectrum. We then decompose it into a set of well-known analytical functions that satisfy the causality and Maxwell’s equations, eliminating the unphysical artifacts possibly contained in numerical solutions. Additional inverse FT of the decomposed impedance function into time domain allows retrieving an effective wake function. Relatively long bunches can be used for the numerical wake potential calculations, significantly reducing the computation time. We show that the method can be applied to a general 3D structure, which opens up the possibility of finding effective wake functions of complicated realistic vacuum chambers.},
  author       = {Skripka, Galina and Nagaoka, Ryutaro},
  issn         = {1098-4402},
  keyword      = {wakefield,impedance,wake potential},
  language     = {eng},
  publisher    = {American Physical Society},
  series       = {Physical Review Special Topics - Accelerators and Beams},
  title        = {Pragmatic method of deducing a wake function for a general 3D structure},
  year         = {2015},
}