[Colloquium] REMINDER: Seminar Announcement: Collaborative Simulation of Radiative Shock Experiments

[Ninfa Mayorga]

Computation Institute Presentation

Speaker: Milad Fatenejad, Flash Center for Computational Science,  
Department of Astronomy and Astrophysics, University of Chicago
Date: September 8, 2011
Time: 1:00 PM - 2:00 PM
Location: The University of Chicago, Searle 240A, 5735 S. Ellis Ave.,  
Argonne National Lab, TCS/Room 5C2 (5172)

Collaborative Simulation of Radiative Shock Experiments

Abstract:
Advances in plasma physics, powerful lasers, and pulsed-power machines  
have made possible detailed exploration and exciting discoveries about  
states of matter at high temperatures and densities. The ongoing  
radiative shock experiments being conducted by the Center for  
Radiative Shock Hydrodynamics (CRASH) use the OMEGA laser facility to  
investigate radiative shocks which are present in a wide range of  
astrophysical phenomena. These experiments drive a collapsed planar  
radiative shock through a Xenon filled shock tube using high power  
lasers. Simulations play an important role in understanding these  
experiments due to the complexity associated with diagnosing and  
performing them. We will describe a new collaboration which has formed  
to use multiple radiation-hydrodynamics codes to model the CRASH  
radiative shock experiments. Earlier attempts to simulate these  
experiments have uncovered various challenges in obtaining agreement  
with experimental results. A new collaboration, l ed by the Flash  
Center for Computational Science, has been created with the goal of  
performing high-fidelity simulations of the radiative shock  
experiments. Unlike earlier efforts, multiple sophisticated radiation- 
hydrodynamics codes are being employed. Relying on simulations  
performed by multiple codes and institutions, including several  
universities and national laboratories, has had several advantages.  
For example, it has uncovered discrepancies in material opacities and  
errors in the simulation codes themselves. It is also leading to an  
increased understanding of the differences between the various  
numerical models utilized in each code. The net result is an  
improvement in the codes and higher confidence in the simulation  
results. This effort is also unique in that it represents the first  
use of the recently implemented HEDP capabilities of the FLASH code  
for modeling a HEDP experiment. Over the past two years, the FLASH  
code, developed at the Flash Center, has had subst antial new  
capabilities incorporated for this purpose. Some notable examples  
include new multi-material equation of state models, radiation  
transport through multigroup diffusion, and a laser ray-tracing  
package. This collaboration has accelerated the development of FLASH  
through extensive use of code-to-code comparisons.