International EMMI Workshop on Plasma Physics at FAIR, GSI Darmstadt, June 21 - 23, 2017

The creation of ultra-high energy density (UHED, >1x10^8 J/cm³) plasmas in compact laboratory setups enables studies of matter under extreme conditions and can be used for the efficient generation of intense x-ray and neutron pulses. An accessible way to achieve the UHED regime is the irradiation of vertically aligned high-aspect-ratio nanowire arrays with relativistic femtosecond laser pulses. These targets have shown to facilitate near total absorption of laser light several micrometers deep into near-solid-density material. We investigate the depth of the volumetric heating and a mechanism causing the wires to pinch, thereby delaying the hydrodynamic expansion and achieving extremely high energy and particle densities.