Magnetoelectrical technique for studying the insulator–metal transition under shock compression

Abstract

The paper describes a magnetoelectrical technique for monitoring the particle velocity in matter acquiring a large electrical conductivity under shock compression. The particle velocity is measured in the electromagnetic skin layer, which travels through matter with a wave velocity. The layer thickness essentially depends on the electrical conductivity of shock-compressed matter. A multielectrode cell also allows the wave velocity to be registered at various spatial bases. Experiments give kinematics parameters of a metallization wave for aluminium powders of varied mass density and particle size. The results unambiguously testify that the conductivity of the aluminium powder arises in the main shock wave carrying full pressure. The results do not confirm the conclusion of Novac et al about metallization of the aluminium powder in an elastic precursor. The thickness of the skin layer for a coarse powder is smaller than the thickness of the shock-compression zone, which offers the opportunity of finding the metallization phase directly in the shock transition zone.