Electrothermal instability evolution on Z-pinch rods and imploding liners pulsed with intense current

Magnetically imploded liners assemble high-energy-density plasmas for radiation effects and inertial confinement fusion experiments. The stagnation pressures and temperatures achieved are limited by the Magneto-Rayleigh-Taylor (MRT) instability, which can grow to large amplitude from a small seed perturbation. While the metallic liners used for experiments on the Sandia National Laboratories Z Facility are typically diamond turned to 10–30 nm rms surface roughness, the observed MRT amplitude is unexpectedly large. Early in the current pulse an electrothermal instability (ETI), driven by non-uniform runaway Ohmic heating, may provide a mass perturbation on the liner's surface which exceeds the machining roughness; ETI may then provide the dominant seed from which MRT grows.