Underwater Electrical Explosion of Wire/Wire Arrays as a Promising Approach to High Energy Density Physics Research

Underwater electrical wire explosion (UEWE) has been demonstrated to be a robust approach in the research of matter at extreme conditions, the main goal of high energy density physics (HEDP). Indeed, applying pulse generators with stored energy of several kJ allows one to achieve
$\geq 10^{8}\mathrm{J}/(\text{kg}\times \mathrm{s})$
energy density deposition rate, pressure of
$> 10^{9}$
Pa, and temperature of several eV. It was shown that UEWE is accompanied by rapid phase transitions of wire material resulting in the formation of a non-ideal, high-resistivity plasma characterized by fast-rising thermal instabilities, allowing conductivity research of different materials at extreme conditions. Additionally, we demonstrated that a planar shock, generated by the explosion of planar wire arrays, can efficiently (~12% energy transfer) accelerate targets. Moreover, the generation of supersonic (~4.5 km/s) water jets by the explosion of a conical wire array was demonstrated. The latter can be used for sub-Mbar pressure formation when interacting with a target. These results show great promise when considering scaling experiments into more powerful pulse generators. Ongoing research of UEWE employs different diagnostics such as high current and voltage measurements, shadow frame and streak imaging, X-ray radiography, and visible spectroscopy. Experimental results are compared to one-and two-dimensional hydrodynamic and magneto-hydrodynamic simulations, which recreate key experimental results, providing additional insight into the complex process occurring during UEWE. In this presentation selected results from recent advancements in studying and applying the aforementioned processes in the field of UEWE to further understanding HEDP will be discussed.