Comparison among different Geant4-DNA physics models of proton transportation in nano-layers

In this paper are presenting a comparison by using experimental data about chemical damage for all possible physics list for Geant4-DNA (Geant4 version 10.02.p01) for protons incident beam interacting with homogeneous nano-layers of water. Associated to the chemical damage it were evaluated: radial profile of energy deposition, profile of energy deposition on depth, number of interactions, proportion among possible processes and stopping power of the incident particle. The application considers water ultra-thin layers of thicknesses from 2 nm to 200 nm with monodirectional and monochromatic (2 MeV to 20 MeV) protons impinging normally on its entrance surface. It was evoked the standard physics list ("G4EmDNAPhysics" class) and other 5 physics list available (names Opt ' up to 5). Concerning the experimental data, the films were bombarded by 2 MeV H+ in vacuum at a HVEE 3 MV Tandetron and X-ray photoelectron spectroscopy was performed on the irradiated samples at Universite de Namur, Belgium. The preliminary results show that radial and depth profile of energy deposition to all physics lists evaluated presented as expected, with exception for the physics list Opt'. This physics list shows a peak of energy deposition at the end of the layer on depth profile. On radial profile it is clear that the secondaries electrons transported by Opt' presented larger range than the presented by other evaluated physics list. It was observed for few simulations considering standard physics list that for thickness above ~350 nm the curve of depth profile achieve it "saturation" and stop the increasing on energy deposition with depth.