Electrical wire explosion in longitudinal magnetic field

Abstract

Summary form only given, as follows. The explosion of tungsten wires of 70 /spl mu/m diameter with a current pulse of /spl sim/70 kA in a microsecond rise time, and in a longitudinal magnetic field is studied. The following parameters are recorded during the experiment: current and voltage on the wire; an optical image of the explosion process with image intensifiers both in streak and frame recording regimes. The development of the Rayleigh-Taylor instability at the moment of plasma dispersion of the exploding wire, and an earlier discovered effect of stabilization in an /spl sim/1 T field are studied. Use of frame registration allowed wavelengths of the developing instability to be identified and the dispersion stabilization traced, taking into account the growth of longitudinal magnetic field strength. A numerical method for an incremental calculation of Rayleigh-Taylor instability growth in the linear stage of the explosion evolution process is realized. Qualitative and quantitative agreement with the optical image, recorded during the experiments, is obtained. Based on this, the numerical method can be used to estimate the threshold magnetic field needed to stabilize the Rayleigh-Taylor instability as a function of wire thickness and current rise time. The recorded stabilization effect of the exploding wire dispersion with weak (having no effect on dispersion dynamics) magnetic field allowed the calibration of EOS models, conductivity and radiation models used in calculations. This calibration could be performed for other substances.