| A first order perturbation expansion is used to describe the onset and growth of the Rayleigh-Taylor instability in a compressible, adiabatic plasma of finite, constant conductivity. A general mode equation is derived, which is shown to reduce to a well known form in the limit of infinite conductivity. The general mode equation is solved numerically for the specific initial current, mass density, and magnetic field profiles typical of one dimensional steady-state rail gun models. Conductivity is shown to play an important role in limiting the growth of disturbances of shorter wavelength; however, the resulting growth rates are large enough to permit full development of the Rayleigh-Taylor instability during accelerations in these devices. |
