Hybrid Multilevel Solvers for Discontinuous Galerkin Finite Element Discrete Ordinate (DG-FEM-SN) Diffusion Synthetic Acceleration (DSA) of Radiation Transport Algorithms

B.O’Malley would like to acknowledge the support of EPSRC under their industrial doctorate programme (EPSRC grant number: EP/G037426/1), Rolls- Royce for industrial support and the Imperial College London (ICL) High Per- formance Computing (HPC) Service for technical support. M.D. Eaton and J. K ́ oph ́ azi would like to thank EPSRC for their support through the fol- lowing grants: Adaptive Hierarchical Radiation Transport Methods to Meet Future Challenges in ReactorPhysics (EPSRC grant number: EP/J002011/1) and RADIANT: A Parallel, Scalable, High Performance Radiation Transport Modelling and Simulation Framework for Reactor Physics, Nuclear Criticality Safety Assessment and Radiation Shielding Analyses (EPSRC grant number: EP/K503733/1).