Determination of point isotropic buildup factors of gamma rays including incoherent and coherent scattering for aluminum, iron, lead, and water by discrete ordinates method

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

OSTI ID:7032835

Kitsos, S; Assad, A; Diop, C M; Nimal, J C ^[1]; Ridoux, P ^[2]

---

1. Centre d'Etudes Nucleaires Saclay, Gif-sur-Yvette (France). Shielding Lab.
2. Electricite de France, Villeurbanne (France)

Exposure and energy absorption buildup factors for aluminum, iron, lead, and water are calculated by the SNID discrete ordinates code for an isotropic point source in a homogeneous medium. The calculation of the buildup factors takes into account the effects of both bound-electron Compton (incoherent) and coherent (Rayleigh) scattering. A comparison with buildup factors from the literature shows that these two effects greatly increase the buildup factors for energies below a few hundred kilo-electron-volts, and thus the new results are improved relative to the experiment. This greater accuracy is due to the increase in the linear attenuation coefficient, which leads to the calculation of the buildup factors for a mean free path with a smaller shield thickness. On the other hand, for the same shield thickness, exposure increases when only incoherent scattering is included and decreases when only coherent scattering is included, so that the exposure finally decreases when both effects are included. Great care must also be taken when checking the approximations for gamma-ray deep-penetration transport calculations, as well as for the cross-section treatment and origin.

• OSTI ID: 7032835
• Journal Information: Nuclear Science and Engineering; (United States), Journal Name: Nuclear Science and Engineering; (United States) Vol. 117:1; 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
ALUMINIUM
BUILDUP
COMPUTER CALCULATIONS
COMPUTER CODES
ELECTROMAGNETIC RADIATION
ELEMENTS
GAMMA RADIATION
HYDROGEN COMPOUNDS
IONIZING RADIATIONS
IRON
LEAD
METALS
NEUTRAL-PARTICLE TRANSPORT
OXYGEN COMPOUNDS
PHOTON TRANSPORT
POINT SOURCES
RADIATION SOURCES
RADIATION TRANSPORT
RADIATIONS
S CODES
TRANSITION ELEMENTS
WATER