The use of an expanded polynomial orthogonal set in approximations to gamma-ray buildup factor data

Journal Article · Wed Jun 01 04:00:00 EDT 1994 · Nuclear Science and Engineering; (United States)

OSTI ID:7103656

Michieli, I ^[1]

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1. Ruder Boskovic Institute, Zagreb (Croatia). Dept. of Technology, Nuclear Energy and Radiation Protection

Buildup factors for various shielding materials exhibit large variations in magnitude and in curve shapes as a function of penetration depth as a result of the stochastic nature of the scattering processes for different incident photon energies. In a quest for adequate functional representation of point isotropic gamma-ray buildup factor data, a family of functions based on an expanded polynomial orthogonal set is introduced. A polynomial-based function approach is validated as a possible choice [besides the well-known geometrical-progression (G-P) function] for point-kernel calculations. Results of approximations to exposure point isotropic buildup factors for water, concrete, and iron with four and for lead and beryllium with five independent parameters of presented function are in good agreement with the basic data within 4%, over the standard data domain. The results are compared with five-parameter G-P function fitting on the maximum-percentage-relative-error basis. The validity of using the independent parameters of the function to interpolate buildup factors for intermediate source energies is ascertained.

• OSTI ID: 7103656
• Journal Information: Nuclear Science and Engineering; (United States), Journal Name: Nuclear Science and Engineering; (United States) Vol. 117:2; ISSN NSENAO; ISSN 0029-5639
• Country of Publication: United States
• Language: English

Related Subjects

663620* -- Physics of Radiations Other Than Neutrons-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BUILDING MATERIALS
BUILDUP
CALCULATION METHODS
COMPARATIVE EVALUATIONS
CONCRETES
DATA
ELECTROMAGNETIC RADIATION
ELEMENTS
EVALUATION
FUNCTIONS
GAMMA RADIATION
HYDROGEN COMPOUNDS
INFORMATION
IONIZING RADIATIONS
KERNELS
LEAD
MATERIALS
METALS
NEUTRAL-PARTICLE TRANSPORT
NUMERICAL DATA
OXYGEN COMPOUNDS
PHOTON TRANSPORT
POINT KERNELS
RADIATION TRANSPORT
RADIATIONS
THEORETICAL DATA
WATER