The Effects of Preheating of a Fine Tungsten Wire and the Polarity of a High-Voltage Electrode on the Energy Characteristics of an Electrically Exploded Wire in Vacuum

Results obtained from experimental and numerical studies of tungsten wires electrical explosion in vacuum are presented. The experiments were performed both with and without preheating of the wires, using positive or negative polarity of a high-voltage electrode. Preheating is shown to increase energy deposition in the wire core due to a longer resistive heating stage. The effect was observed both in single wire and wire array experiments. The evolution of the phase state of the wire material during explosion was examined by means of one-dimensional numerical simulation using a semiempirical wide-range equation of state describing the properties of tungsten with allowance made for melting and vaporization.Comment: 9 pages, 9 Postscript figure

Study of thin metallic film explosion in vacuum

An experiment with Al, Cu and Ni exploding foils was carried out at a current density of (0.5-1)•108 A/cm{2} through the 6-[mu]m foil with a current density rate of about (0.5-1)•108 A/cm{2} centerdots. To record the metal foil effervescence during the foil explosions, a two-frame radiographic system was used. It was shown that the duration of the explosion resistive phase was considerably lower than the metal boiling time. The foil energy deposition is equal to 30-70% of the sublimation energy

Soft x-ray measurements of z

This article reports the experimental characterization of a z-pinch driven-vacuum hohlraum. The authors have measured soft x-ray fluxes of 5 x 10{sup 12} W/cm{sup 2} radiating from the walls of hohlraums which are 2.4--2.5 cm in diameter by 1 cm tall. The x-ray source used to drive these hohlraums was a z-pinch consisting of a 300 wire tungsten array driven by a 2 MA, 100 ns current pulse. In this hohlraum geometry, the z-pinch x-ray source can produce energies in excess of 800 kJ and powers in excess of 100 TW to drive these hohlraums. The x-rays released in these hohlraums represent greater than a factor of 25 in energy and more than a factor of three in x-ray power over previous laboratory-driven hohlraums