The analysis of noise in magnetic recording tapes has been approached
from a fresh perspective. Magnetic microstructure, which is dependent
on physical microstructure, applied field and magnetic history, is tre
ated as a spatial dynamical system. An introduction to nonlinear spati
al dynamics is presented with a particular emphasis on chaos. These pr
inciples are applied to noise time series generated by moving a tape,
bearing a fixed magnetic microstructure, past a read head. Evidence is
provided that noise from the media is deterministic in origin, being
chaotic rather than random. A qualitative difference in dynamical beha
viour is observed between oriented and unoriented tape systems. In add
ition, it is shown that one of the dynamical quantifiers we employ, th
e pointwise fractal dimension, varies systematically as a function of
remanent state as the tapes are taken through a de demagnetisation pro
cess. The fractal dimension is interpreted in terms of the magnetic mi
crostructure. In conclusion, the nature of the dynamics underlying noi
se in magnetic recording media is considered.