REPEATED INTERRUPTION AND RESTORATION OF CURRENT IN LIQUID-METALS AS A NONLINEAR PHENOMENON

The evolution of large-scale convective instabilities in a plasma-like medium in the field of its own electric current is considered in the framework of the magneto-hydrodynamics of incompressible viscous resis tive liquids. The simplest low-mode model of the nonlinear interaction of perturbations is proposed and analytically investigated. According to this model, if the amplitude of the current exceeds its critical v alue, the effective resistance of the medium can break into oscillatio ns. The model has enabled us to estimate with reasonable exactness the threshold commutation current and the frequency of current oscillatio n for experiments on repeated interruption and restoration of electric current through the In-Ga eutectic.