FOSLS for Neutron/Photon Transport at LLNL


Lawrence Livermore National Laboratory, CASC L-661, P.O. Box 808, Livermore, CA 94551


We give an overview of our fosls codes for neutron/photon transport at LLNL. A brief description of the Boltzmann transport equation, the finite element discretizations, and the numerical algorithms will be given. In particular, we describe the least-squares finite element formulations (trilinear in space and spherical harmonic in angle, trilinear in space and piecewise constant in angle, trilinear/macro-element in space and spherical harmonic in angle) and the multigrid algorithms implemented in our codes. Numerical examples illustrating discretization accuracy, multigrid scalability, and processor scalability will be presented.