Rayleigh–Taylor instability of a plasma–vacuum boundary in the limit of a large Larmor radius

Abstract

The Rayleigh–Taylor instability of a plasma–vacuum boundary is studied with the aid of an ideal one-fluid Hall model corresponding to the limit of a large ion Larmor radius. The global Rayleigh–Taylor instability mode, whose growth rate is Γ(k)=(gk)1/2, still exists in this case, but is not necessarily the dominating one. The exact upper bound for the growth rates of all the other instability modes is found in the low-beta limit. For large wave numbers the growth rate of the fastest instability mode is estimated as Γmax(k)=gk/Ωi.