Dynamic evolution of the resistive wall mode in flowing plasmas

The dynamic evolution of the resistive wall mode (RWM) is numerically studied in the slab geometry with and without a plasma flow. The linear growth rate of the RWM is dependent on the resistive wall location (d) and the plasma flow (v(0)). The RWM can be stabilized completely by a plasma flow only if the resistive wall is close enough to the plasma boundary (d < 1.15a). The direction of the plasma flow has an effect on stabilization. The field-aligned flow exhibits the strongest suppressing effect. On the other hand, the shear in the plasma flow has a weak effect on the linear evolution of the RWM. In the nonlinear phase, the amplitude of the perturbed magnetic energy linearly increases with time but very slowly, so that the RWM can be considered as nearly saturated. The saturation can be attributed to flux piling up on the resistive wall. The saturation level decreases with increasing v(0). A field-aligned flow gives the largest reduction of the saturation amplitude.