Stability of the experimental and numerical spheromaks with shear toroidal flow induced by magnetic reconnection

Abstract This work presents a laboratory experiment on the magnetic reconnection of two self-sustained, tilt-unstable spheromaks. Experimental observations, confirmed by a developed 3D Hall-MHD model, demonstrate that magnetic reconnection of these spheromaks suppresses the tilt instability by reducing the amplitudes of disruptive low-number toroidal modes. The strong toroidal component of outflow jets generates a shear toroidal velocity, which may disrupt the coherent structure of these modes, leading to their suppression. The damping rate of toroidal magnetic perturbations was found to be exponentially related to the shear toroidal velocity. Following the end of reconnection, the growth rate of the modes is linearly proportional to the decrease in shear velocity.