Solenoidal current flows for filamentary conductors

The "uniform" current density inside a filamentary (stranded) conductor must be found by a pre-processing step before the magnetic field produced by it can be computed. A previously published method for achieving this is very general, but gives a current density that is not solenoidal. Here, an algorithm is described for generating a solenoidal current density. The densities before and after applying the algorithm are separately used as the source in the computation of the magnetostatic field of a square coil, and of the deflection yoke of a color picture tube. The nonsolenoidal source leads to significant field errors; the corrected source gives the expected field.