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Abstract: In this work scaling laws in laboratory astrophysics are studied. It is shown that mathematical models governing radiation hydrodynamics-driven phenomena are invariant under the homothetic group transformation and can be rescaled according to several types of scaling laws. This property is valid for both optically thick and optically thin materials and it allows a correct and rigorous connection between astrophysical objects or phenomena and laboratory experiments. This approach is applied to astrophysical jets and radiative shocks where advantages as well as difficulties are pointed out. [ABSTRACT FROM AUTHOR]

In this paper, new results on radiative shocks generated by a high power laser in a xenon gas cell are presented. Several shock parameters were measured: temperature, radial expansion and velocity, as well as the electron density in the radiative precursor and its velocity. Multiple laser shot allowed the investigation of physical trends changing initial conditions (laser energy and initial gas pressure). Results are compared with one- and two-dimensional radiative hydrodynamic simulations. The experiments were carried out at the LULI Laboratory. [ABSTRACT FROM AUTHOR]

The interface velocity of iron partially releasing into a lithium fluoride (LiF) window has been measured using VISAR technique. Corrections to the fringe-per-velocity relationship are presented. A good agreement with hydrodynamic simulations is found at laser intensities <2×1013 W/cm2. For higher intensities, velocities appear to be lower than the numerical predictions. A strong modification of compressed LiF index of refraction behavior might explain such a discrepancy. [ABSTRACT FROM AUTHOR]