2D numerical study of the radiation influence on shock structure relevant to laboratory astrophysics

Abstract

Context. Radiative shocks are found in various astrophysical objects and particularly at different stages of stellar evolution. Studying radiative shocks, their topology, and thermodynamical properties is therefore a starting point to understanding their physical properties. This study has become possible with the development of large laser facilities, which has provided fresh impulse to laboratory astrophysics. Aims. We present the main characteristics of radiative shocks modeled using cylindrical simulations. We focus our discussion on the importance of multi-dimensional radiative-transfer effects on the shock topology and dynamics. Methods. We present results obtained with our code HERACLES for conditions corresponding to experiments already performed on laser installations. The multi-dimensional hydrodynamic code HERACLES is specially adapted to laboratory astrophysics experiments and to astrophysical situations where radiation and hydrodynamics are coupled. Results. The importance of the ratio of the photon mean free path to the transverse extension of the shock is emphasized. We present how it is possible to achieve the stationary limit of these shocks in the laboratory and analyze the angular distribution of the radiative flux that may emerge from the walls of the shock tube. Conclusions. Implications of these studies for stellar accretion shocks are presented.

Simulation of radiative shock waves in Xe of last PALS experiments

“…To finish the description of the target, we take free boundary conditions at the physical contour (the use of wall in the target design avoids the use of any albedo coefficient for the radiation at the boundaries [35]) of the system and the Au/CH foil of the target will be illuminated by a laser coming from the bottom of Fig. 2.…”

Radiative precursors driven by converging blast waves in noble gases

“…A numerical study of wall albedo effects in the cylindrical shock tube geometry typical of laser-driven experiments is presented in Ref. 19. Liner wall albedo effects have been neglected in the interpretation of the data in this paper.…”

3D modeling of accretion shocks in young stellar objects : Simulation of laboratory experiments

“…The laser energy is converted into mechanical energy (Stehle et al 2009). Prior simulations with HERACLES had revealed multidimensional effects in such shocks, such as lateral radiative losses (González et al 2006;González et al 2009). In order to characterize the radiative structure and spectroscopic signatures of these shocks, we use IRIS to post-process the results from HERACLES.…”