TEMPORAL EVOLUTION OF THE HYDRODYNAMIC INSTABILITY OF THE BOUNDARY BETWEEN THE DENSE CORE AND THE PLASMA CORONA DURING NANOSECOND EXPLOSIONOF WIRES

We report the results of investigations of the interaction of a plasma corona with a dense, cold core formed on the discharge axis in the in itial stage of the nanosecond electrical explosion of metal wires. The internal structure of the dense core and the dynamics of processes oc curring in it were studied by a specially developed method of multifra me x-ray shadow photography. The large observed amplitudes of the dist urbances of the boundary between the dense core and the Z-pinch corona , which are comparable to the core radius, are attributed to the devel opment of Rayleigh-Taylor and Kelvin-Helmholtz hydrodynamic instabilit ies. (C) 1998 American Institute of Physics. [S0021-3640(98)00308-9]