Quantifying advanced tape medium noise

An investigation of the tape medium noise mechanism analyzed the magnetizat ion fluctuation produced by an incremental de erase process in a variety of modern metal-particle tape media. It examined the wavelength characteristi cs of the noise and compared the integrated noise during the reverse de era se process with in situ remanent hysteresis curves. The integrated noise po wer followed the square of the first field derivative of the remanent hyste resis curve, (dM/dH)(2), showing that spatial fluctuation of the recording field inside the medium is a major source of the tape medium noise. It excl uded spatial fluctuation of the medium coercivity as a possible noise sourc e by comparing results from recording heads with two very different gap len gths. A quantitative analysis of the medium noise spectra at different eras e currents indicated that interfacial roughness at the magnetic coating bac kside in some dual-layer media is a major source of medium noise. The concl usion: The main mechanism of the medium noise in advanced tape media is the head medium spacing fluctuation due to surface roughness.