Boltzmann-transport-equation algorithms for infinite-slab buildup and albedo factors. Rept. for 21 Nov 88-30 Sep 90

Technical Report · Sun Sep 30 04:00:00 EDT 1990

OSTI ID:5930635

Dunn, W L; Yacout, A M; O Foghludha, F

This report describes the development of improved algorithms for use in the Mathematical Radiation Environment Model for Ships (MREMS) code, which estimates dose equivalent at a matrix of many detector points due to a set of gamma-ray and neutron emitting source points. The algorithms consist of models with adjustable parameters, which are averageable over arbitrary source spectra, for buildup and albedo factors; these models can be used directly in the point-kernal model that MREMS employs. Buildup and albedo factors were calculated for six materials in a point source, slab, point-detector geometry using a decomposition of the solution to the Boltzmann transport equation (and appropriate boundary conditions) into single- and multiple-scatter components. A rigorous solution for the single-scatter component was used that improves the efficiency of the calculations. A detailed model-fitting procedure was employed to fit these factors to simplified models, and the model constants were evaluated for each of several source energies. Finally, a procedure was implemented to determine average model constants for arbitrary source spectra. Slab buildup and albedo factors are presented for various source-slab-detector configurations, both in tabular form and in graphs that also show the fitted models.

• Research Organization: Quantum Research Services, Inc., Durham, NC (United States)
• OSTI ID: 5930635
• Report Number(s): AD-A-242015/6/XAB; CNN: N60921-88-C-0175
• Country of Publication: United States
• Language: English

Related Subjects

440102 -- Radiation Instrumentation-- Radiation Dosemeters
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
663610* -- Neutron Physics-- (1992-)
663620 -- Physics of Radiations Other Than Neutrons-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ABSORPTION
ALBEDO
ALGORITHMS
BARYONS
BOLTZMANN EQUATION
CHEMICAL REACTIONS
COMPUTER CODES
DATA
DECOMPOSITION
DIFFERENTIAL EQUATIONS
DOSEMETERS
DOSES
DOSIMETRY
EFFICIENCY
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ENERGY
EQUATIONS
FERMIONS
FORTRAN
GAMMA RADIATION
HADRONS
INFORMATION
IONIZING RADIATIONS
M CODES
MATERIALS
MATHEMATICAL LOGIC
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
NEUTRAL-PARTICLE TRANSPORT
NEUTRON TRANSPORT
NEUTRONS
NUCLEONS
PARTIAL DIFFERENTIAL EQUATIONS
PHOTON TRANSPORT
POINT SOURCES
PROGRAMMING LANGUAGES
RADIATION DOSES
RADIATION SOURCES
RADIATION TRANSPORT
RADIATIONS
SHIPS
SLABS
SPECTRA