SIMULATION AND ANALYSIS OF AN X-RAY-HEATED BORON-NITRIDE FOIL

We analyze an experiment performed at the Nova laser facility, at Lawr ence Livermore National Laboratory, in which x rays, produced by a gol d burn-through foil, heated an 1800-Angstrom boron-nitride (BN) foil. The BN foil was not hydrodynamically tamped and therefore provides an excellent example for testing our success at modeling systems with lar ge density and temperature gradients. A time-integrated absorption spe ctrum was obtained. This spectrum reveals He-like and H-like boron fea tures, He-like nitrogen features, as well as Li-Like satellites to the resonance Lines for both boron and nitrogen. The ALTAIR radiation hyd rodynamics code and the TOTAL line-shape code were the basic instrumen ts used in the analysis. Simulations address the temporal evolution of the temperature and density profiles as well as the ionization balanc e for the x-ray driven boron nitride foil. A synthesized spectrum is c ompared with the experimental absorption spectrum, and particular atte ntion is given to the Li-Like satellite structure. The analysis of thi s seemingly simple experiment clearly reveals both current strengths a nd inadequacies in modeling hot dense matter.