  For the investigations of thermally activated magnetization reversal in
systems of classical magnetic moments numerical methods are desirable. We
present numerical studies which base on time quantified Monte Carlo methods
where the long-range dipole-dipole interaction is calculated with the aid of
fast Fourier transformation. As an example, we study models for ferromagnetic
nanowires comparing our numerical results for the characteristic time of the
reversal process also with numerical data from Langevin dynamics simulations
where the fast Fourier transformation method is well established. Depending on
the system geometry different reversal mechanism occur like coherent rotation,
nucleation, and curling.
