  High-speed visible imaging of sub-microsecond electric explosion of wires at
the low specific energy deposition threshold reveals three distinct modes of
wire failure as capacitor charge voltage and energy deposition are increased.
For 100 micron diameter gold-plated tungsten wires of 2 cm length, deposited
energies of 1.9 eV/atom produces a liquid column that undergoes hydrodynamic
breakup into droplets with radii of order of wire diameter on timescales of 200
microseconds. Instability growth, column breakup, and droplet coalescence
follow classic Rayleigh-Plateau predictions for instability of fluid column.
Above 3.2 eV/atom of deposited energy, wires are seen to abruptly transition to
an expanding mixture of micron scale liquid-droplets and vapor within one frame
(less than 3.33 microseconds), which has been termed phase explosion in
literature. Between these two limits, at 2.5 eV/atom of deposited energy, wire
radius is unchanged for the first 10 microseconds before the onset of a rapid
expansion and disintegration that resembles homogeneous nucleation of
mechanically unstable bubbles. Thermodynamic calculations are presented that
separate cases by temperature obtained during heating: below boiling point,
near boiling point, and exceeding boiling point.
