3D MHD studies of dynamic processes in the reversed-field pinch

A causal mechanism for the self-reversal process in the reversed-field pinch (RFP) is proposed. The mechanism is based on non-linear reconnection driven by a single helical kink instability. As a result of non-linear deformation by the kink instability, radial magnetic fields are generated, which are conveyed by axial plasma flows induced by the kink instability and eventually reconnected at the encounter points of the flows. Consequently, the radial fields are converted to reversed and normal toroidal fields in the outer and inner regions, respectively, and a reversed-field-pinch configuration is realized. Magnetohydrodynamic simulations have clearly confirmed the validity of the proposed reversal mechanism. (author)