Transient magnetic field calculations with TRIDIF

TRIDIF is a time-dependent diffusion version of the well-known PANDIRA-POISSON-TRIM triangular mesh magnet code. Modifications which allow TRIDIF to treat field diffusion in materials with time-varying permeabilities are described. A heuristic dipole alignment model which described major and minor hysteresis loops and frequency dependence has been included to provide the requisite permeabilities. Good agreement between the measured and computed magnetic fields was found for a simple test experiment.