Asynchronous, Heterogeneous, High-Performance Plasma Simulations

We present MASS-APP, a state-of-the-art plasma physics simulation tool designed for modern supercomputer architectures. Leveraging a novel velocity space discretization of the Vlasov/Boltzmann equations allows for an efficient implementation GPUs. This discretization uses a spectral expansion of asymmetrically weighted Hermite functions. The number of terms in the expansion can vary according to real space location to capture fine scale phenomena. This provides a clean mathematical formulation for simulating problems with non-uniform resolution requirements. With this goal of simulating dynamic problems and the high-costs of memory movement, MASS-APP utilitizes an asynchronous, task-based, performance-portable library, FleCSI. FleCSI supports multiple backends including MPI, Legion, and HPX for distributed parallelism and Kokkos for performance portability. In this talk, we present the details of MASS-APP and discuss results highlighting the performance benefits of task based runtimes on modern HPC architectures.