pF3D Simulations of Laser-Plasma Interactions in National Ignition Facility Experiments

The laser-plasma interaction code pF3D is used to simulate laser-plasma interactions in National Ignition Facility experiments. This article describes the optimizations performed on pF3D to enable scaling to a million or more processes. The authors begin with a brief description of NIF experiments and then describe pF3D with a focus on the features that are needed to get good performance at scale. The performance of message passing, disk I/O, and code steering are key issues that impact scalability and are discussed in detail. Scaling studies on IBM Blue Gene/L, IBM Blue Gene/P, Cray XE6, and IBM Blue Gene/Q systems are used as examples. The article concludes with a comparison of the backscattered light measured in NIF experiments and computed in the pF3D simulation.