Micromagnetic calculations of eddy currents with time-varying fields

This paper extends a recently presented program for solving the eddy current problem in a cylindrical geometry, by investigating the effect of time-varying fields. When the applied field is turned off, wall motion slows by several orders of magnitude, but since the wall energy can be reduced by reducing the length of the wall, it continues to move, albeit much more slowly. Reversing the applied field has the effect of nucleating the opposite kind of wall which propagates inward and eventually annihilates the previous wall.