On the relative importance of the different initial conditions that seed the electrothermal instability

The electrothermal instability (ETI) plays an important role in the thermal and hydrodynamic evolution of dense metallic systems driven with extreme electrical pulses. The instability grows from gradients in the electrical resistivity, and is responsible for hampering numerous applications of pulsed-power technology. For the first time, metal surfaces have been tracked with approximately 20 um accuracy throughout an experiment. This tracking reveals no clear correlation between target defects and non-uniform thermal emissions indicative of the ETI. Additionally, the relative influence of surface topography and purity of metal composition will be compared. Data indicate enhanced stability to ETI may be found by employing ultra-pure materials.