Validity of the geometric-progression formula in approximating gamma-ray buildup factors

Journal Article · Mon Sep 01 04:00:00 EDT 1986 · Nucl. Sci. Eng.; (United States)

OSTI ID:6964913

Harima, Y; Sakamoto, Y; Tanaka, S; Kawai, M

A geometric-progression (G-P) method formula, B/sub r/ = 1 + (B-1) . (K/sup x/-1)/(K-1), accurately represents the buildup factor data as a function of distance for the following reasons: 1. The value of parameter B corresponds to that of the buildup factor at 1 mfp, which is the integration of a basic spectrum for a specified material and for a specified source energy. 2. The variation of parameter K with penetration represents the photon dose multiplication and the change in the shape of the spectrum. Exposure buildup factors for point isotropic sources in an infinite medium approximated by the G-P fitting parameters are in good agreement with the basic data calculated by the PALLAS code, including that of boron for low energies, and of lead, including the effects of bremsstrahlung and fluorescence. The validity of using the G-P parameters to interpolate the buildup factor in ..mu..r and in E is ascertained. Furthermore, the extrapolation to the buildup data for depths above 40 mfp is examined.

• Research Organization: Tokyo Institute of Technology, Research Lab. for Nuclear Reactors, Oh-okayama, Meguro-ku, Tokyo 152
• OSTI ID: 6964913
• Journal Information: Nucl. Sci. Eng.; (United States), Journal Name: Nucl. Sci. Eng.; (United States) Vol. 94:1; ISSN NSENA
• Country of Publication: United States
• Language: English

Related Subjects

654001* -- Radiation & Shielding Physics-- Radiation Physics
Shielding Calculations & Experiments
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACCURACY
BORON
BREMSSTRAHLUNG
BUILDUP
COMPUTER CODES
DEPTH
DIMENSIONS
DISTANCE
DOSES
DOSIMETRY
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ELEMENTS
EQUATIONS
EXTRAPOLATION
FLUORESCENCE
GAMMA DOSIMETRY
GAMMA RADIATION
INTERPOLATION
IONIZING RADIATIONS
ISOTROPY
LEAD
LUMINESCENCE
MASSLESS PARTICLES
METALS
MULTIPLICATION FACTORS
NUMERICAL SOLUTION
P CODES
PHOTONS
RADIATION DOSES
RADIATIONS
SEMIMETALS
TESTING
VALIDATION