106 research outputs found
Influence of equation of state on interpretation of electrical conductivity measurements in strongly coupled tungsten plasma
We study the influence of equation-of-state (EOS) model on the interpretation
of electrical conductivity measurements in strongly coupled plasma of tungsten
by Korobenko et al. (2002 Plasma Physics Reports 28(12) 1008--1016). Three
different semiempirical EOS models for tungsten are used. Discrepancies in
obtained thermodynamic parameters and specific resistivity values as compared
with calculation results of Korobenko et al. are analysed.Comment: 11 pages, 5 Postscript figures, accepted for publication in J. Phys.
A: Math. Ge
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
Suppression of ablation in femtosecond double pulse experiments
We report the physical reasons of a curious decrease in the crater depth
observed for long delays in experiments with femtosecond double pulses.
Detailed hydrodynamic modeling demonstrates that the ablation mechanism is
dumped when the delay between the pulses exceeds the electron-ion relaxation
time. In this case, the interaction of the second laser pulse with the
expanding target material leads to the formation of the second shock wave
suppressing the rarefaction wave created by the first pulse. The evidence of
this effect follows from the pressure and density profiles obtained at
different delays after the first laser pulse.Comment: Submitted to one of the APS Journal
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