THE AVERAGE POWER-DENSITY SPECTRUM OF THE READBACK VOLTAGE FROM PARTICULATE MEDIA

Present experimental data shows that the noise changes with the frequency of the written signal. In this paper an analysis of this dependency is given by means of a simplified model for the particle interactions. Although such a model does not go into the more intricate physics of the phenomenon, it gives a good macroscopic interpretation for the interaction which fits the observed data extremely well. The clusters' contribution to the spectrum is clearly revealed here: the shoulders around the signal spikes are translations of the square of the amplitude of the Fourier transform of the probability density of the subclusters' position within the clusters.