Initial electron energy spectra in water irradiated by photons with energies to 1 GeV

Technical Report · Wed Feb 01 04:00:00 EST 1984

DOI:https://doi.org/10.2172/5208802· OSTI ID:5208802

Todo, A. S.; Hiromoto, G.; Turner, J. E.; Hamm, R. N.; Wright, H. A.

This work was undertaken to provide basic physical data for use in the dosimetry of high-energy photons. Present and future sources of such photons are described, and the relevant literature is reviewed and summarized. Calculations were performed with a Monte Carlo computer code, PHOEL-3, which is also described. Tables of initial electron and positron energies are presented for monoenergetic photons undergoing single interactions in water. Photon energies to 1 GeV are treated. The code treats explicitly the production of electron-positron pairs, Compton scattering, photoelectric absorption, and the emission of Auger electrons following the occurrence of K-shell vacancies in oxygen. The tables give directly the information needed to specify the absolute single-collision kerma in water, which approximates tissue, at each photon energy. Results for continuous photon energy spectra can be obtained by using linear interpolation with the tables. (Continuous spectra can also be used directly in PHOEL-3.) The conditions under whch first-collision kerma approximate absorbed dose are discussed. A formula is given for estimating bremsstrahlung energy loss, one of the principal differences between kerma and absorbed dose in practical cases. 31 references, 4 figures, 18 tables.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5208802
• Report Number(s): ORNL/TM-8987; ON: DE84007564
• Country of Publication: United States
• Language: English

Related Subjects

654001* -- Radiation & Shielding Physics-- Radiation Physics
Shielding Calculations & Experiments
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ABSORPTION
BASIC INTERACTIONS
COMPTON EFFECT
COMPUTER CODES
DATA
DOSIMETRY
ELASTIC SCATTERING
ELECTROMAGNETIC INTERACTIONS
GAMMA DOSIMETRY
HYDROGEN COMPOUNDS
INFORMATION
INTERACTIONS
NEUTRAL-PARTICLE TRANSPORT
NUMERICAL DATA
OXYGEN COMPOUNDS
P CODES
PAIR PRODUCTION
PHOTOELECTRIC EFFECT
PHOTOELECTROMAGNETIC EFFECTS
PHOTON TRANSPORT
RADIATION TRANSPORT
SCATTERING
THEORETICAL DATA
WATER
X-RAY DOSIMETRY