Speaker: Dr. Pierre-Alexandre Gourdain, Cornell University
Abstract: High energy density plasmas turn out to be a wonderful platform to study warm dense matter, high yield fusion energy or astrophysical phenomena. The key ingredient to reach megabars of pressures: geometrical focusing. For instance, a flat metallic foil driven by radial currents, which converge onto a central pin, achieves local densities on the order of 1022 electrons/cm-3 and temperatures in the keV range. More precisely, this foil goes through an ablation phase, characterized by an axial collimated plasma jet, a compression phase, forming a central Z-pinch, and finally an expansion phase, where super-Alfvenic flows carry plasma away. Due to large Reynolds (107 to 109) and magnetic Reynolds numbers (101 to 103), radial foil plasmas reproduce more or less astrophysical jets and outflows. Using these laboratory experiments as intuitive guides, it is possible to highlight the physical mechanisms that might cause such astrophysical formations.