Half-range acceleration for one-dimensional transport problems

Journal Article · Thu Dec 31 04:00:00 EST 1998 · Transactions of the American Nuclear Society

OSTI ID:298300

Zika, M R ^[1]; Larsen, E W ^[2]

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1. Lawrence Livermore National Lab., CA (United States)
2. Univ. of Michigan, Ann Arbor, MI (United States)

Researchers have devoted considerable effort to developing acceleration techniques for transport iterations in highly diffusive problems. The advantages and disadvantages of source iteration, rebalance, diffusion synthetic acceleration (DSA), transport synthetic acceleration (TSA), and projection acceleration methods are documented in the literature and will not be discussed here except to note that no single method has proven to be applicable to all situations. Here, the authors describe a new acceleration method that is based solely on transport sweeps, is algebraically linear (and is therefore amenable to a Fourier analysis), and yields a theoretical spectral radius bounded by one-third for all cases. This method does not introduce spatial differencing difficulties (as is the case for DSA) nor does its theoretical performance degrade as a function of mesh and material properties (as is the case for TSA). Practical simulations of the new method agree with the theoretical predictions, except for scattering ratios very close to unity. At this time, they believe that the discrepancy is due to the effect of boundary conditions. This is discussed further.

• OSTI ID: 298300
• Report Number(s): CONF-981106--
• Journal Information: Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 79; ISSN 0003-018X; ISSN TANSAO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BOUNDARY CONDITIONS
CONVERGENCE
FOURIER ANALYSIS
ITERATIVE METHODS
ONE-DIMENSIONAL CALCULATIONS
TRANSPORT THEORY