Peculiarities of an Electrical Explosion of Flat Conductors in the Current Skinning Mode

Abstract

The propagation of a nonlinear magnetic-field diffusion wave generated under the condition of an electrical explosion of flat conductors is investigated in the current skinning mode. Using a MIG terrawatt generator, a number of experiments are performed on electrical explosion of a copper foil, 100 μm in thickness and 5 mm in width, at the current amplitude up to 2.5 MA and its rise rate 100 ns. It is shown that under these conditions a plasma channel is formed by approximately 75-th ns from the current onset. The estimations, made considering the magnetic field enhancement on the foil edges, demonstrate that about 70–80 ns are required for the nonlinear magnetic-field diffusion wave to propagate from the foil edge to its center. A good agreement of the experimental data and the estimates suggested a conclusion that the plasma channel formation is due to the convergence of the nonlinear diffusion wave towards the longitudinal foil axis.