Date: 2026-09-05 Purpose: 2D cos-theta dipole with an iron yoke.

What it shows

A cos-theta dipole cross section with 68 bulk conductor blocks, air, and an iron yoke using the RoxieIron B-H curve from bhdata.hdf5. The current ramps to 8498 A over 10 s. The deck models one quarter of the magnet and demonstrates the two symmetry planes: the x-axis plane keeps the current sign and is declared symmetry; the y-axis plane inverts it and is declared antisymmetry. The comments in input.conf explain why.

Files

file	role
costheta.geo	geometry; mesh it with gmsh
input.conf	deck
Allrun, Allclean	wrappers for the shared launcher

Run

gmsh -2 costheta.geo -o costheta.msh

../../build/bin/belfem # or mpirun -np 4 ../../build/bin/belfem

Or ./Allrun, which does both steps.

Shared launcher

../scripts/Allrun generates the mesh, chooses ranks and threads, and can submit to Slurm; ../scripts/Allclean removes run output. To use them from this directory, copy the two wrapper scripts Allrun and Allclean from examples/helix/ here and run ./Allrun (./Allrun --dry-run prints the plan first). If you copy this deck out of the tree, copy examples/scripts/ along with it and point the wrappers at its new location. The launcher does not build plugins; do that step by hand as described above. Per-deck settings go in a run.conf next to input.conf; see ../scripts/README.md.