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The density distribution is important information in the investigation of electrical exploding wires in the air. In this study, the density profiles of the electrons, tungsten atoms, and air at different instants were reconstructed based on a two-wavelength interferometry method. The experiment was carried out on a 1 kA, 0.1 kA/ns pulsed current generator, with a fine tungsten wire (10 μm in diameter). The laser probing images of the exploding products showed a two-layer structure, exhibiting a shunting discharge scenario. The fitted expanding trajectory of the dense core indicates that the expansion of the wire starts at the instant of the voltage drop. The reconstructed densities show the distribution of particles in the expansion process of the exploding wire. It is found that the wire core has a tube-like structure, and the plasma channel is located around the core boundary. [ABSTRACT FROM AUTHOR]

Based on electrical and optical diagnostics and electrostatic calculations, the relationship between distribution of radial electric field and energy deposition of electrically exploded wires in vacuum was investigated. Copper plates with different diameters were used to modify the distribution of radial electric field along wire surface in the experiments. The calculated radial electric field showed good consistency with the wire core outline in optical images, and there is a saturated positive correlation between maximum specific energy (Esm) and averaged radial field strength over the wire length. It can be concluded that the direction and amplitude of radial electric field significantly affects Esm and dominates the structure of energy deposition. [ABSTRACT FROM AUTHOR]

The evolution of single- and dual-wire Z-pinch of 8- \(\mu \) m W was investigated by X-ray backlighting using an X-pinch X-ray source. The experiments were carried out on the pulsed-power generator PPG-I (400 kA/500 kV/100 ns), which was designed and constructed by the Department of Electrical Engineering of Tsinghua University. To scale the mass density distributions at different explosion time, a mass step wedge including eight tungsten layers was fabricated and inserted between the object Z-pinch and the X-ray film. By a large number of imaging experiments, the physical images of coronal plasma formation and interwire plasma merging were obtained. Based on the X-ray photos of 8- \(\mu \) m W and mass step wedge, the mass density distributions at different explosion time were drawn, and the conductance curve of time dependence of 8- \(\mu \) m W was also calculated using waveform of voltage and current. [ABSTRACT FROM PUBLISHER]

Electrical explosion of wire provides a practical approach to the experimental measurement of dynamic polarizability of metal atoms with high melting and boiling temperatures. With the help of insulation coating, a section of tungsten wire was transformed to the plasma state while the near electrode region was partially vaporized, which enabled us to locate the “neutral-region” (consisting of gaseous atoms) in the Mach-Zehnder interferogram. In this paper, the polarizability of the tungsten atom at 532 nm was reconstructed based on a technique previously used for the same purpose, and the basic preconditions of the measurement were verified in detail, including the existence of the neutral region, conservation of linear density of tungsten during wire expansion, and neglect of the vaporized insulation coating. The typical imaging time varied from 80 ns to as late as 200 ns and the reconstructed polarizability of the tungsten atom was 16 ± 1 Å3, which showed good statistical consistency and was also in good agreement with the previous results. [ABSTRACT FROM AUTHOR]