Transition Parameter “a” Variation of Individual Writing Process

The jitter noise is the dominant media noise in perpendicular recording. It is proportional to cross track correlation and the square of transition parameter “a” [1]. Besides the efforts of minimizing the value of “a,” it is also very important to control the variation of “a” in each individual writing process. In this work, from the time domain head media spacing measurement, there is a significant signal amplitude variation arising from individual writing process at the same writing conditions. After removing the change related to disk morphology, the amplitude difference of individual writing reflects the variation of “a.” Reducing such “a” variation is helpful to control the transition noise.