Velocity shear effect on Rayleigh–Taylor vortices in nonuniform magnetized plasmas

Abstract

In this paper, the effect of velocity shear on Rayleigh–Taylor vortices has been demonstrated. An inhomogeneous plasma is considered with a density profile such that the diamagnetic drift velocity Vn=(cTe/eB)dn0/dx is a constant and includes the effect of an ambient poloidal shear flow Veq(x)=V⊥0′(x−x0)y. The final equation describing the stationary Rayleigh–Taylor vortex is shown to have the structure of a nonlinear Poisson equation, where the nonlinearity arises essentially because of the velocity shear term. This equation has been solved numerically and it has been shown that qualitatively new two-dimensional monopole vortex solutions may be obtained in the appropriate parameter space. Therefore, a new important nonlinear effect related to equilibrium shear flow has been identified in the calculations of Rayleigh–Taylor vortices which results in monopole-like solutions in plasmas.