ACCELERATION OF A 2-DIMENSIONAL, 2-ENERGY GROUP NEUTRON NOISE SOLVER BASED ON A DISCRETE ORDINATES METHOD IN THE FREQUENCY DOMAIN

The acceleration of the convergence rate is studied for a neutron transport solver to simulate 2-D, 2-energy-group noise problems in frequency domain. Coarse Mesh Finite Difference (CMFD) method compared Diffusion Synthetic Acceleration (DSA) method. Numerical tests are performed using heterogeneous system configurations with different boundary conditions. CMFD scheme leads better rate. results also show that can accelerate wide range perturbation frequencies almost equal efficiency. An unstable behavior nevertheless observed purely reflective Stabilization techniques such as performing multiple sweeps, underrelaxing flux update, and lpCMFD investigated improvements be obtained.