Interaction of radiatively cooled plasma jets with neutral gases for laboratory astrophysics studies

A supersonic (Mach∼2–3), radiatively cooled plasma jet is produced by the ablation of aluminium plasma from a radial foil, a disc subjected to a ∼1.4 MA, 250 ns current from the MAGPIE pulsed-power generator. The ablated plasma converges on axis, producing a steady and collimated jet with axial velocities reaching ∼100 km/s. The study of jet-ambient interactions is achieved by introducing a neutral gas above the foil using a fast valve with a supersonic gas nozzle. The system has flexibility to study different interaction geometries in order to vary critical dimensionless parameters for astrophysical studies. In particular the effects of radiative cooling on the working surface of the jet are strongly affected by varying the gas composition. Experimental results are compared to numerical simulations using the 3-D MHD code GORGON.