Numerical simulation of feedback stabilization of the tearing mode in a rotating plasma

The suppression of the tearing mode by means of feedback is studied in a rotating plasma cylinder. The feedback is produced by a coil whose winding is specified by cos var-phi, var-phi = mθ - kz. It is shown that when a resonant surface is present in the rotating plasma the current in the feedback winding generates a magnetic flux in the plasma with cos var-phi and sin var-phi angular dependence. The processes of particle capture is explained. The rotational instability which arises because of the repulsion between the feedback and tearing-mode currents, which interferes with suppression of the tearing mode, is absent when the plasma rotates sufficiently rapidly. In this feedback dependence the form of the plasma current profile determines whether there can be an instability in the induced current resulting from the presence of the feedback