Modeling and analysis of overwrite in thick particulate media

Overwrite in tape recording is studied by three dimensional micromagnetic simulation. We simulate thick tape media of randomly distributed ellipsoidal particles with proper orientation distributions. Our initial calculations examine the overwriting of a low frequency NRZI signal by a higher frequency signal. The simulation allows us to look at the signal spectrum at each depth into the medium before and after overwrite. We find that the residual low frequency signal is due to contributions from all depths in the media. The effect of record equalization on overwrite ratios is also studied.