TY - JOUR
T1 - Astrophysical radiative shocks
T2 - From modeling to laboratory experiments
AU - González, Matthias
AU - Stehlé, Chantal
AU - Audit, Edouard
AU - Busquet, Michel
AU - Rus, Bedrich
AU - Thais, Frédéric
AU - Acef, Ouali
AU - Barroso, Patrice
AU - Bar-Shalom, Abraham
AU - Bauduin, Daniel
AU - Kozlovà, Michaela
AU - Lery, Thibaut
AU - Madouri, Ali
AU - Mocek, Tomas
AU - Polan, Jiri
PY - 2006/10/1
Y1 - 2006/10/1
N2 - Radiative shock waves are observed around astronomical objects in a wide variety of environments, for example, they herald the birth of stars and sometimes their death. Such shocks can also be created in the laboratory, for example, by using energetic lasers. In the astronomical case, each observation is unique and almost fixed in time, while shocks produced in the laboratory and by numerical simulations can be reproduced, and investigated in greater detail. The combined study of experimental and computational results, as presented here, becomes a unique and powerful probe to understanding radiative shock physics. Here we show the first experiment on radiative shock performed at the PALS laser facility. The shock is driven by a piston made from plastic and gold in a cell filled with xenon at 0.2 bar. During the first 40 ns of the experiment, we have traced the radiative precursor velocity, that is showing a strong decrease at that stage. Three-dimensional (3D) numerical simulations, including state-of-art opacities, seem to indicate that the slowing down of the precursor is consistent with a radiative loss, induced by a transmission coefficient of about 60% at the walls of the cell. We infer that such 3D radiative effects are governed by the lateral extension of the shock wave, by the value of the opacity, and by the reflection on the walls. Further investigations will be required to quantify the relative importance of each component on the shock properties.
AB - Radiative shock waves are observed around astronomical objects in a wide variety of environments, for example, they herald the birth of stars and sometimes their death. Such shocks can also be created in the laboratory, for example, by using energetic lasers. In the astronomical case, each observation is unique and almost fixed in time, while shocks produced in the laboratory and by numerical simulations can be reproduced, and investigated in greater detail. The combined study of experimental and computational results, as presented here, becomes a unique and powerful probe to understanding radiative shock physics. Here we show the first experiment on radiative shock performed at the PALS laser facility. The shock is driven by a piston made from plastic and gold in a cell filled with xenon at 0.2 bar. During the first 40 ns of the experiment, we have traced the radiative precursor velocity, that is showing a strong decrease at that stage. Three-dimensional (3D) numerical simulations, including state-of-art opacities, seem to indicate that the slowing down of the precursor is consistent with a radiative loss, induced by a transmission coefficient of about 60% at the walls of the cell. We infer that such 3D radiative effects are governed by the lateral extension of the shock wave, by the value of the opacity, and by the reflection on the walls. Further investigations will be required to quantify the relative importance of each component on the shock properties.
KW - Laboratory astrophysics
KW - Laser plasmas
KW - Radiative shock waves
KW - Radiative transfer
UR - http://www.scopus.com/inward/record.url?scp=33947203998&partnerID=8YFLogxK
U2 - 10.1017/S026303460606071X
DO - 10.1017/S026303460606071X
M3 - Article
AN - SCOPUS:33947203998
VL - 24
SP - 535
EP - 540
JO - Laser and Particle Beams
JF - Laser and Particle Beams
SN - 0263-0346
IS - 4
ER -