Collaborative comparison of simulation codes for high-energy-density physics applications

Advances in plasma physics, powerful lasers, and pulsed-power machines have made possible experiments allowing detailed exploration and discoveries about states of matter at high energy densities. Since these experiments are expensive to perform and difficult to diagnose, numerical simulations have played an important part in designing and understanding them. A number of sophisticated radiation-hydrodynamic codes have been developed to perform this task. We will describe a new collaboration to compare three of these codes for a variety of test problems. Current members of this collaboration are the Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan, the FLASH Center at the University of Chicago, and Los Alamos National Laboratory (LANL). These code comparisons have enabled us to understand differences in numerical methods, physical approximations, microphysical parameters, etc. The net result has been an improvement in the codes and higher confidence in the simulation results. This paper presents the results of a subset of these comparison tests.