User's manual for PHOEL-3, a Monte Carlo computer code for calculating initial energies of electrons and positrons produced in water irradiated by photons with energies up to 1 GeV

Technical Report · Sun Aug 01 04:00:00 EDT 1982

OSTI ID:5226873

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

The Monte Carlo computer code, PHOEL-3, which is described here, replaces an earlier code, PHOEL-2, for generating the initial energies of electrons and positrons produced in water by irradiation with photons having an arbitrary energy spectrum up to 1 GeV. The code handles input photons individually on the basis of the energy-dependent cross sections for the physical processes treated, which are the photoelectric effect, Compton scattering, and pair and triplet production. Options exist for (1) following each photon through successive Compton scattering events until it disappears by photoelectric absorption or pair production, (2) allowing at most only a single Compton-scattering event per input photon, and (3) turning the photoelectric effect on or off. If energetically possible, it is assumed that a photoelectron originates in the oxygen K shell; otherwise, it originates in the L shell. An Auger electron of energy 0.508 keV is assumed to be emitted following the creation of a K vacancy. The code can calculate both the relative number of electrons and positrons at various initial energies and the absolute number per unit photon fluence, which can be used directly to compute kerma. For comparison with other work, detailed calculations made with PHOEL-3 give results that agree with the work of Cormack and Johns for photon energies of up to 25 MeV. The numerical data used in PHOEL-3, the mathematical treatment of the calculation, and the operation of the code are described in this manual. PHOEL-3 can be obtained from the Radiation Shielding Information Center at Oak Ridge National Laboratory. The present code differs from the earlier PHOEL-2 by (1) including pair and triplet production, (2) calculating the absolute number of electrons and positrons in addition to the relative number, and (3) extending the photon energy range from 2 MeV up to 1 GeV.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5226873
• Report Number(s): ORNL/TM-8259; ON: DE82019726
• Country of Publication: United States
• Language: English

Related Subjects

654001* -- Radiation & Shielding Physics-- Radiation Physics
Shielding Calculations & Experiments
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BASIC INTERACTIONS
COMPTON EFFECT
COMPUTER CODES
DOCUMENT TYPES
ELASTIC SCATTERING
ELECTROMAGNETIC INTERACTIONS
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
ENERGY RANGE
ENERGY SPECTRA
FERMIONS
GAMMA RADIATION
GEV RANGE
HYDROGEN COMPOUNDS
INTERACTIONS
IONIZING RADIATIONS
LEPTONS
MANUALS
MONTE CARLO METHOD
NEUTRAL-PARTICLE TRANSPORT
OXYGEN COMPOUNDS
PAIR PRODUCTION
PHOTON TRANSPORT
POSITRONS
RADIATION TRANSPORT
RADIATIONS
SCATTERING
SPECTRA
WATER