Exploding wire arrays for single-shot hydrodynamic instability experiments

Hydrodynamic instabilities are of fundamental importance to geophysical and astrophysical flows, planetary sciences, and to applications such as fuel combustion or inertial confinement fusion. These can be seen on at all scales, from the structure of proto-stellar jets and nebulae, to the inertial confinement fusion experiments where instabilities can mix cold, dense, high Z plasma into fusion fuel significantly reducing yield. Measuring how the hydrodynamic instabilities evolve is crucial to providing quantitative comparison to theory and simulations, yet many experiments are limited to exploring relatively small region of parameter space in Mach and Atwood numbers, or provide only a few measurements per experiment, requiring control of the initial conditions (ICs).

We present a technique for the investigation of shock-driven hydrodynamic phenomena in arbitrary geometries. The technique consists of a pulsed-power driven resistive wire array explosion diagnosed by multi-MHz synchrotron radiography. It offers a set of advantages: (1) The shockwave geometry can be shaped to the requirements of the experiment, (2) the pressures (>300MPa) generated by the explosion enable the use of solid targets with well-characterised ICs, (3) the multi-MHz radiography enables all data acquisition within a single experiment, eliminating uncertainty regarding the ICs, and (4) the radiography allows density measurements. Simultaneously, the use of a synchrotron X-ray source allows the samples to be volumetrically characterised at a high spatial resolution using synchrotron-based microtomography.