Spartan

• Energy/Temperature Discretization
  • Solves 2 T + Multi-Group Even-Parity Equations
  • Can yoke T_e and T_i together to make 1 T
  • Can use a single-group radiation treatment to make 3 T
• Angular Discretization
  • Uses Simplified Spherical Harmonics -- SP_N
  • Can do a P₁ (diffusion-like) solution
• Spatial Discretization
  • SP_N decouples equations into many diffusion equations
  • Diffusion equations are solved by Augustus
• Temporal Discretization
  • Linearized implicit discretization
  • Equivalent to one pass of a Newton solve
  • Iteration strategy:
    • Source iteration
    • DSA acceleration
    • LMFG acceleration