Coarse-mesh rebalance methods compatible with the spherical harmonic fictitious source in neutron transport calculations

Technical Report · Wed Oct 01 04:00:00 EDT 1975

DOI:https://doi.org/10.2172/4143136· OSTI ID:4143136

Miller, Jr, W F

The coarse-mesh rebalance method, based on neutron conservation, is used in discrete ordinates neutron transport codes to accelerate convergence of the within-group scattering source. Though very powerful for this application, the method is ineffective in accelerating the iteration on the discrete-ordinates-to- spherical-harmonics fictitious sources used for ray-effect elimination. This is largely because this source makes a minimum contribution to the neutron balance equation. The traditional rebalance approach is derived in a variational framework and compared with new rebalance approaches tailored to be compatible with the fictitious source. The new approaches are compared numerically to determine their relative advantages. It is concluded that there is little incentive to use the new methods. (3 tables, 5 figures) (auth)

• Research Organization: Los Alamos Scientific Lab., N.Mex. (USA)
• DOE Contract Number: W-7405-ENG-36
• NSA Number: NSA-33-008449
• OSTI ID: 4143136
• Report Number(s): LA--6145-MS
• Country of Publication: United States
• Language: English

Related Subjects

*NEUTRON TRANSPORT THEORY-- COMPARATIVE EVALUATIONS
641600*
ITERATIVE METHODS
N68100* --Physics (Nuclear)--Neutron Interactions with Matter
QUADRATURES
SPHERICAL HARMONICS
VARIATIONAL METHODS