Harkening back to the genesis of LLNL’s inertial confinement fusion (ICF) program, codes have played an essential role in simulating the complex physical processes that take place in an ICF target and the facets of each experiment that must be nearly perfect. Many of these processes are too complicated, expensive, or even impossible to predict through experiments alone. With only a few National Ignition Facility (NIF) laser shots per year to test target and experimental designs, computer modeling provides designers with valuable insights into which ideas are more likely to work. With the road to ignition beset with multiple hurdles, a host of codes (and codes within codes) were brought to bear on the problem. Codes have been ingrained in the overall NIF design loop. They’re used to help design the experiment, to model the target capsule and iterate on designs, to answer questions from experimentalists and to understand what occurred post-experiment. The knowledge gained from each shot goes back into the codes to improve them. Read more at LLNL News.