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

Technical Report ·
OSTI ID:5930635

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