Exposure buildup factors of high-energy gamma rays for water, concrete, iron, and lead

Journal Article · Wed Apr 01 04:00:00 EST 1987 · Nucl. Technol.; (United States)

OSTI ID:5365159

Hirayama, H

Exposure buildup factors for plane normal sources have been calculated with an electron gamma shower Monte Carlo code, EGS4, for water, concrete, iron, and lead in the 10 to 100 MeV range. Electron reactions like multiple scattering, collision, and continuous energy loss are taken into account together with bremsstrahlung. The buildup factors in this energy region are affected very much by the energy loss mechanism of electrons and positrons in the medium. The energy of electrons or positrons in lead is mainly converted to photons via the bremsstrahlung reaction; therefore, buildup factors increase rapidly with the increase of the photon energy. In the case of water, the energy of electrons or positrons is mainly spent in ionization or excitation. Buildup factors for water decrease gradually to 40 MeV and increase gradually above that energy. The buildup factors in each medium are calculated for eight-source energy from 10 to 100 MeV for penetration depths as great as 10 mfp.

• Research Organization: National Lab. for High Energy Physics, Oho-machi, Ibaraki-ken 305 (JP)
• OSTI ID: 5365159
• Journal Information: Nucl. Technol.; (United States), Journal Name: Nucl. Technol.; (United States) Vol. 77:1; ISSN NUTYB
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
BREMSSTRAHLUNG
BUILDING MATERIALS
C CODES
COLLISIONS
COMPUTER CODES
CONCRETES
DOSE RATES
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY LOSSES
ENERGY RANGE
GAMMA RADIATION
HYDROGEN COMPOUNDS
IONIZING RADIATIONS
IRON
IRRADIATION
LEAD
LOSSES
MATERIALS
METALS
MEV RANGE
MEV RANGE 10-100
MONTE CARLO METHOD
OXYGEN COMPOUNDS
RADIATIONS
SCATTERING
TRANSITION ELEMENTS
WATER