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

• Published in: Physics of plasmas 2013-06, Vol.20 (6)
• Main Authors: Hochhaus, D. C., Aurand, B., Basko, M., Ecker, B., Kühl, T., Ma, T., Rosmej, F., Zielbauer, B., Neumayer, P.
• Format: Article
• Language: English
• Subjects: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AXIAL SYMMETRY; COMPARATIVE EVALUATIONS; Density; ELECTRON TEMPERATURE; ELECTRONS; ENERGY ABSORPTION; ENERGY LOSSES; Fluid dynamics; Fluid flow; Heating; Hydrodynamics; ION TEMPERATURE; ISENTROPIC PROCESSES; LASER TARGETS; LASER-PRODUCED PLASMA; Lasers; Micrometers; PLASMA DIAGNOSTICS; PLASMA EXPANSION; PLASMA HEATING; PLASMA PRODUCTION; TEMPERATURE GRADIENTS; TIME RESOLUTION; TITANIUM; Wire; X-RAY RADIOGRAPHY
• ISSN: 1070-664X; 1089-7674
• DOI: 10.1063/1.4810801

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 Kα-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.