Time dependence of readout signal and media noise

The change with time in the readout signal and the media noise affected by thermal fluctuation was investigated by micromagnetic computer simulation. It was found that the logarithm of the time taken for the readout signal to decay by a constant factor was roughly in proportion to the value of K/sub u/V/kT regardless of the presence or absence of the distribution in the grain size. The lines representing the logarithm of decay time against K/sub u/V/kT were almost parallel to each other when the decay factor was changed. It was found that the time dependence of the rate of the decay in the readout signal is similar to that of the rate of the increase in the media noise and that the change in the media noise preceded the change in the readout signal.