STABILITY OF AN IMPLODING SPHERICAL-SHELL

It is shown that, in an imploding spherical shell, the surface instabilities are of two different types. The first, which occurs at the outer surface, is the well-known Rayleigh-Taylor instability. The second instability occurs at the inner surface. The characteristics of this instability are similar to those of amplified sound waves in an imploding plasma shell. It is suggested that this instability is driven by the amplified sound waves.