Experimental Measurements of Hydrodynamic Instabilities on Nova of Relevance to Astrophysics

Large lasers such as Nova allow the possibility of achieving regimes of high-energy densities in plasmas of millimeter spatial scales and nanosecond timescales. In those plasmas where thermal conductivity and viscosity do not play a significant role, the hydrodynamic evolution is suitable for benchmarking hydrodynamics modeling in astrophysical codes. Several experiments on Nova examine hydrodynamically unstable interfaces. A typical Nova experiment uses a gold millimeter-scale hohlraum to convert the laser energy to a 200 eV blackbody source lasting about a nanosecond. The X-rays ablate a planar target, generating a series of shocks and accelerating the target. The evolving areal density is diagnosed by time-resolved radiography, using a second X-ray source. Data from several experiments are presented and diagnostic techniques are discussed.