  The damping of collective rotational motion is studied microscopically,
making use of shell model calculations based on the cranked Nilsson deformed
mean-field and on residual two-body interactions, and focusing on the shape of
the gamma-gamma correlation spectra and on its systematic behavior. It is shown
that the spectral shape is directly related to the damping width of collective
rotation, \Gammarot, and to the spreading width of many-particle many-hole
configurations, \Gammamu. The rotational damping width is affected by the shell
structure, and is very sensitive to the position of the Fermi surface, besides
mass number, spin and deformation. This produces a rich variety of features in
the rotational damping phenomena.
