FOCUS = Finding Flexible Optimized Coils Using Space curves.

[Stellarators and tokamaks (hereafter referred to as unknotatrons) have a magnetic axis in the shape of a circle, which is a special class of knot called an "unknot".]
  1. A detailed description of all subroutines etc. is given below.
  2. Please direct questions/suggestions to Caoxiang Zhu,, subject=FOCUS.
  3. Subroutines from Oculus are used.

subroutine description
globals (input) Description of input namelists.
numrec (numerics) Some miscellaneous numerical routines.
initial (initialize) Read input file, initialize global variables.
surface (boundary) The plasma boundary is read from file.
rdknot (knot) Reads knot parameters from file. (Redundant?)
rdcoils (coils) Fourier description of coils.
knotxx (brief) Description.
iccoil (coil geometry) Specification of coil geometry.
bfield (field) Computes magnetic field.
bnormal (bnormal) Calculate total bnormal and its derivatives.
torflux (toroidal flux) Construct toroidal flux constraints.
tlength (tlength) Calculate total length cost functon and its derivatives. (czhu)
equarcl (equarcl) EQUAl ARC Length constraints.
specwid (specwid) Spectral width condensation.
coilsep (coilsep) Constraints for finding maximum coil-coil separation.
nlinear ( nlinear ) Nonlinear solver using NAG routine.
fdcheck (fd check) Read input file, initialize global variables.
denergy (energy) Construct “energy” (cost function).
descent (optimize) Minimize “energy” via a differential flow.
restart (restart) Writes output and restart files.
diagnos (diagnostic) Poincaré plot.
exinput (diagnostic) Prepare input information for other codes.
identfy (identify) Poincaré plot.
bnftran(bnftran) Transforming the Bnormal distribution into Fourier harmonics.
focus (main) Main program.
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