Dynamical origin of shear flow induced modifications of magnetic islands

Abstract

A generalized Newcomb equation that incorporates inertial contributions from equilibrium shear flows as well as finite β contributions is derived in a cylindrical geometry. It is shown from numerical solutions of this equation that the stability parameter Δ' can be significantly influenced by flow as it becomes a sensitive function of the global profiles of the magnetic field and flow velocity. These results can have important implications for the nonlinear evolution of magnetic islands in the presence of flows.