FIG. 2.

The use of different models in different regions. Panel A: Parameter file setting physics lists for different regions to combine macroscopic and nanometer scale simulations with several parameters that should be considered. Panel B: Protons (1 MeV) traversing a gold nanoparticle (GNP) surrounded by liquid water. In water, the transport is handled by Monte Carlo track-structure simulations, whereas in the GNP the transport is handled by condensed-history Monte Carlo (Geant4 Livermore EM physics processes). Proton tracks are shown with blue lines and electron tracks are shown with red lines connected with yellow points that represent inelastic and elastic interactions.