8.22 TFBFirSetup

• description: TFBFirSetup computes FIR (Finite Impulse Response) filter coefficients for use with TFBDRIVER elements to perform turn-by-turn transverse feedback. The method uses time-domain least-squares fitting [47].
• examples:

  TFBSetup -twiss Basic.twi -pickup XPICKUP -driver XDRIVER -plane x -output xfb.param -terms 6

• synopsis:

  TFBFirSetup -twiss twissFile -pickup elementName -driver elementName -plane {x|y} -output filename -terms numberOfTerms

• switches:
  • -twiss — A twiss parameter file from elegant. The beamline used for the computations must include a TFBDRIVER and TFBFEEDBACK element for the plane in question.
  • -pickup — Specifies the name of the pickup element in the lattice. One and only one occurrence of the element is required in the twissFile. Note that generally the name of the pickup should be all uppercase.
  • -driver — Specifies the name of the driver element in the lattice. One and only one occurrence of the element is required in the twissFile. Note that generally the name of the driver should be all uppercase.
  • -plane — Specifies the plane of the feedback.
  • -output — Specifies output filename to which FIR configuration is written. The file should be loaded with load_parameters, e.g.,
    &load_parameters  
        filename = xfb.param,  
        change_defined_values = 1  
    &end

  • -terms — Number of terms in the filter, between 1 and 30, inclusive.
• author: M. Borland, ANL/APS.
• acknowledgments: H. Shang, C.-Y. Yao.