X-ray radiographic expansion measurements of isochorically heated thin wire targets

Solid density matter at temperatures ranging from 150 eV to < 5 eV has been created by irradiating thin wire targets with high-energy laser pulses at intensities ≈ 10 18 W/cm 2. Energy deposition and transport of the laser-produced fast electrons are inferred from spatially resolved K-spectroscopy. Time resolved x-ray radiography is employed to image the target mass density up to solid density and proves isochoric heating. The subsequent hydrodynamic evolution of the target is observed for up to 3 ns and is compared to radiation-hydrodynamic simulations. At distances of several hundred micrometers from the laser interaction region, where temperatures of 5-20 eV and small temperature gradients are found, the hydrodynamic evolution of the wire is a near axially symmetric isentropic expansion, and good agreement between simulations and radiography data confirms heating of the wire over hundreds of micrometers.