Geant4 Validation Studies
| Visualization of a water cylinder (length = 30 cm, radius = 10 cm) irradiated by a 202 MeV proton pencil beam in Geant4. Blue lines are positive particles (protons) and green lines are neutral particles (photons and neutrons). The penetration depth of the protons is visible, as is the widening of the proton density profile close to the Bragg peak. |
| Lateral energy deposition profile in above cylinder. Energy depositions for various Geant4 models and the SHIELD-HIT Monte Carlo code are shown. |
| Neutron fluences at various angles off beam axis from an aluminum cylinder (length = 12 cm, radius = 8 cm) irradiated by a 256 MeV proton pencil beam. Comparison is made to experimental data taken from M. M. Meier, et al., Nucl. Sci. Eng., 104, 339 (1990). |
The results shown here were generated using Geant4 version 5.2p02. Geant4 was configured to use standard electromagnetic physics, data-driven low-energy neutron transport and three models of hadronic physics at intermediate-energies. Results for different hadronic physics models are labeled by: G4BIC for the Binary Cascade model, G4LEAD for the leading-particle biased G4Mars5GeV model, and G4LEPPC for the low-energy parameterized model together with a pre-compound model at lower energies.