Linear Analysis of Axial Sheared Flow in Astrophysical Jets

A linear analysis of axial sheared flow in magnetohydrodynamic (MHD) jets with helical magnetic fields is presented. A linearized set of ideal MHD equations allows the investigation of plasmas with both magnetic shear and flow shear included in the equilibrium profile. These equations are integrated numerically by following the linear development in time of an initial seed perturbation. Global instability growth rates are obtained after the numerical solution converges to the fastest growing mode. It is shown that axial sheared flow reduces the growth of current-driven instabilities in plasma jets with constant magnetic pitch P = rB _z /B _θ.