  A number of applications utilise the energy focussing potential of imploding
shells to dynamically compress matter or magnetic fields, including magnetised
target fusion schemes. This paper examines the effect of fluid rotation on the
Rayleigh-Taylor (RT) driven growth of perturbations at the inner surface of an
imploding cylindrical liquid shell which compresses a gas-filled cavity. The
shell was formed by rotating water in solid body rotation prior to the
piston-driven implosion, which was propelled by a modest external gas pressure.
The fast rise in pressure in the gas-filled cavity at the point of maximum
convergence results in an RT unstable configuration where the cavity surface
accelerates in the direction of the density gradient at the interface. The
experimental arrangement allowed for visualization of the cavity surface during
the implosion using high-speed videography, while offering the possibility to
provide geometrically similar implosions over a wide range of initial angular
velocities such that the effect of rotation on the interface stability could be
quantified. A model developed for the growth of perturbations on the inner
surface indicated that the RT instability may be suppressed by rotating the
liquid shell at a sufficient angular velocity so that the net surface
acceleration remains opposite to the interface density gradient throughout the
implosion. Rotational stabilisation of high-mode-number perturbation growth was
examined by collapsing nominally smooth cavities and demonstrating the
suppression of spray-like perturbations that appear on RT unstable cavity
surfaces. Experiments observing the evolution of low-mode-number perturbations,
prescribed using a mode-6 obstacle plate, showed that the RT-driven growth was
suppressed by rotation, while geometric growth remained along with significant
non-linear distortion of the perturbations near final convergence.
