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GFWIGGLER

Tracks through a wiggler using generate function method of J. Bahrdt and G. Wuestefeld (BESSY, Berlin, Germany).
Parallel capable? : yes
Parameter Name Units Type Default Description
L $M$ double 0.0 Total length
B_MAX $T$ double 0.0 Maximum on-axis magnetic field at gap=GAP0 and equal longitudinal phases of PHASE_1,2,3,4
SHIM_SCALE   double 1 Scaling factor of shim correction field.
DX $M$ double 0.0 Misaligment.
DY $M$ double 0.0 Misaligment.
DZ $M$ double 0.0 Misaligment.
TILT $RAD$ double 0.0 Rotation about beam axis.
PERIODS   long 0 Total number of wiggler periods. Include end poles
STEP   long 1 Number of normal periods to track for each step
ORDER   long 0 Order=3 including the 3rd order terms. Otherwise using 2nd order formula.
END_POLE   long 1 The ending poles are treated as 2 half periods at each sides of the wiggler with reducing field strength, such as 0.25, -0.75, ..., 0.75, -0.25. Periods has to $>$ 2
SHIM_ON   long 0 Include shim correction
INPUT_FILE   STRING NULL Name of SDDS file with By harmonic data given at GAP0 and equal longitudinal phases.
SHIM_INPUT   STRING NULL Name of SDDS file with shim field integral harmonic data given at GAP0.
SYNCH_RAD   long 0 Include classical synchrotron radiation?
ISR   long 0 Include incoherent synchrotron radiation (scattering)?

Tracks through a wiggler using generate function method of J. Bahrdt and G. Wuestefeld (BESSY, Berlin, Germany).
Parameter Name Units Type Default Description
ISR1PART   long 1 Include ISR for single-particle beam only if ISR=1 and ISR1PART=1
X0 $M$ double 0.0 Offset of magnet row center in meter.
GAP0 $M$ double 0.0 Nominal magnetic gap.
D_GAP $M$ double 0.0 Delta gap: actual gap - nominal gap
PHASE_1 $RAD$ double 0.0 Longitudinal phase of the first row (top right)
PHASE_2 $RAD$ double 0.0 Longitudinal phase of the second row (top left)
PHASE_3 $RAD$ double 0.0 Longitudinal phase of the third row (bottom left)
PHASE_4 $RAD$ double 0.0 Longitudinal phase of the fourth row (bottom right)
VERBOSITY   long 0 A higher value requires more detailed printouts related to computations.
GROUP   string NULL Optionally used to assign an element to a group, with a user-defined name. Group names will appear in the parameter output file in the column ElementGroup





N.B.: at present this element is not included in computations of beam moments (moments_output command).

This element simulates a wiggler or undulator using the generate function method given by J. Bahrdt and G. Wüstefeld (``Symplectic tracking and compensation of dynamic field integrals in complex undulator structures,'' PRSTAB 14, 040703, 2011.).

To use the element, one must supply an SDDS file giving harmonic analysis of the wiggler field. The field expansion used by the code is for a wiggler working at the nominal gap and provide pure horizontal deflecting to the on-axis beam. See CWIGGLER, horizontal wiggler with normal poles, for detail explaination of the field expansion and format of the input file. Besides the required columns of Cmn, KxOverKw, KyOverKw, and KzOverKw by the CWIGGLER elements, two more input columns are needed:

If a file include all required columns from CWIGGLER and GFWIGGLER then user can use either of the both methods for simulating a horizontal planar wiggler.

An universal wiggler field, which be used for generating an arbitrary polarization, can be derived by given different longitudinal phase parameters: PHASE_1,2,3,4. The photon energy can be varied by a non-zero D_GAP value.


next up previous
Next: HISTOGRAM Up: Element Dictionary Previous: FTRFMODE
Robert Soliday 2014-06-26