Radiative Shocks and Instabilities in Colliding Supersonic Plasma Jets

Radiative shocks and transition to turbulence are active research frontiers in High Energy Density Plasmas for both astrophysical and Inertial Confinement Fusion applications. The structure of stagnation regions formed due to collision of supersonic plasma jets can be strongly affected by radiative cooling [2] and the presence of magnetic fields, leading to unstable shocks and turbulent plasmas.

Here, we present an investigation of radiative shocks and stagnated plasma regions in counter-streaming supersonic plasma flows interacting within an ambient magnetic field. The colliding plasma flows () are generated by the ablation of solid silicon targets driven by a radiation pulse from a wire array Z-Pinch [1] at the MAGPIE Pulsed - Power Generator facility (1.4MA, 240ns rise-time). An ambient magnetic field along the plasma expansion direction is sustained by the current-currying Z – pinch plasma.

Experiments show the formation of a shock at the middle plane of the interaction region and the consequent development to a dense stagnated plasma layer. A combination of Thomson Scattering measurements and laser-probing interferometry were used to measure plasma density, temperature and flow velocity while an optical self-emission camera captured the overall dynamic. In addition, recent progress on the development of the imaging refractometer [3] technique is also discussed as a promising diagnostic to study radiatively cooled plasmas and transition to turbulence.