The effect of sheared equilibrium plasma rotation on the stability of tearing modes in an ohmic (low plasma β) regime is investigated. It is found, by means of numerical MHD simulations in a cylindrical geometry, that plasma rotation in the equivalent toroidal direction can result both on the increase or decrease of the instability growth rate. Anomalous perpendicular plasma viscosity and plasma rotation shear at the modes’
rational surface play a key role on assessing the effect of shear flow. While destabilising for low viscosity plasmas (ratio of the resistive to viscous diffusion time scales τR/τV<<1), for viscous plasmas (τR/τV>1) shear flow reduces the growth rate. Above a given threshold in the rotation shear (that depends on the ratio τR/τV) a tearing mode, unstable in the absence of rotation, can be stabilised. |
Trabalhos Científicos 
Comunicações a Reuniões Científicas