MCNPX270 LLNL Fission Model

Technical Report · Mon Apr 18 04:00:00 EDT 2011

DOI:https://doi.org/10.2172/1063223· OSTI ID:1063223

Mckinney, Gregg W. ^[1]; Hendricks, John S. ^[1]; Verbeke, Jerome M. ^[2]; Hagmann, Chris ^[2]; Wright, Doug ^[2]

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1. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
2. Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)

The LLNL fission model is an available option in MCNPX version 2.7.0. It was developed at Lawrence Livermore National Laboratory and we have collaborated to implement it in MCNPX. We report here our observations and assessments of the LLNL fission model in MCNPX relative to alternative treatments in MCNPX. The LLNL fission model is the only way for MCNPX to produce correlated prompt gammas from prompt fission, delayed fission, spontaneous fission, and photofission. The LLNL fission model also produces fission neutrons and gammas with the correct multiplicities for induced fission, spontaneous fission, and photofission. The exact modeling of the neutron- and photon-induced fission process enables coincidence counting of fission neutrons and gammas. Comparisons were made to the MCNPX default fission capability which uses ACE table physics and the default fmult fission multiplicity capability. Also, several corrections were made in MCNPX27E and these are described.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 1063223
• Report Number(s): LA-UR--11-02644
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
97 MATHEMATICS AND COMPUTING