Author: Ellison, J.A.
Paper Title Page
TUP023 Modeling CSR in a Vacuum Chamber by Partial Fourier Analysis and the Discontinuous Galerkin Method 419
 
  • D. A. Bizzozero, J.A. Ellison
    UNM, Albuquerque, New Mexico, USA
  • R.L. Warnock
    SLAC, Menlo Park, California, USA
 
  Funding: Work supported by DOE contracts DE-FG-99ER41104 and DE-AC03-76SF00515.
We con­tinue our study of CSR* from a bunch on an ar­bi­trary curved orbit in a plane, which used a Fourier trans­form in s-ct. The vac­uum cham­ber has rec­tan­gu­lar cross sec­tion with pos­si­bly vary­ing hor­i­zon­tal width. We use the slowly vary­ing am­pli­tude ap­prox­i­ma­tion, and in­voke a Fourier ex­pan­sion in the ver­ti­cal co­or­di­nate y, which meets the bound­ary con­di­tions on the top and bot­tom plates and makes con­tact with the Bessel equa­tion of the fre­quency do­main treat­ment. The fields are de­fined by a PDE in s and x, first order in s, which is dis­cretized in x by fi­nite dif­fer­ences (FD) or the dis­con­tin­u­ous Galerkin method (DG). We com­pare re­sults of FD and DG, and also com­pare to our ear­lier cal­cu­la­tions in 3D (parax­ial) which did not use the Fourier se­ries in y*,**. This ap­proach pro­vides more trans­parency in the phys­i­cal de­scrip­tion, and when only a few y-modes are needed, pro­vides a large re­duc­tion in com­pu­ta­tion time.
* See FEL13 Proceedings MOPSO06: http://accelconf.web.cern.ch/AccelConf/FEL2013/papers/mopso06.pdf
** See PRST-AB 7 054403 (2004) and Jpn. J. Appl. Phys. 51 016401 (2012).