Exnihilo Transport Methods Manuals Revision 0

Technical Report · Sun Mar 01 00:00:00 EST 2015

DOI:https://doi.org/10.2172/3007865· OSTI ID:3007865

Evans, Thomas ^[1]; Davidson, Greg ^[1]; Jarrell, Josh ^[1]; Hamilton, Steven ^[1]; Johnson, Seth ^[1]; Pandya, Tara ^[1]

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1. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

Exnihilo is a transport code system that contains both deterministic and stochastic (Monte Carlo) solvers. The deterministic solvers are contained in the Denovo [1] package while the Monte Carlo solvers are imple- mented in the Shift package. This document explains the mathematical and numerical methods employed within Exnihilo. It is not a users guide, nor is it a code developer's manual. Naturally, there is cross-over between the code implmentation and mathematical description of any given method, and these are included for the purpose of greater understanding where appropriate. The purpose of this document is to formally describe the equations that are solved by the various packages inside of Exnihilo. In general, linkages are not made between a given numerical method and the Exnihilo code base. This is largely due to the fact that the Exnihilo code base changes far more rapidly than the actual methods that it is solving. Thus, this documentation would go rapidly out of date if cross-references were made between the methods and the code that implements them. Instead, developers are encouraged to look at the Doxygen-produced code documentation that explains what each translation unit in the code is doing. Where necessary we will make distinctions between methods that are implemented in Exnihilo and methods that are documented to provide better understanding of the broader field and provide context for the choosen methods in Exnihilo.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 3007865
• Report Number(s): CASL-U--2015-0080-000
• Country of Publication: United States
• Language: English