An investigation of neutron direct damages at energies of 0.1-2 MeV on the DNA molecules with atomic structure deduced using Geant4 toolkit

This study proposes a method to estimate RBE of fast neutrons using Monte Carlo simulations. This approach is based on the combination of an atomic resolution DNA geometrical model and Monte Carlo simulations for tracking particles. Atomic positions were extracted from the Protein Data Bank. The GEANT4 code was used for tracking the secondary particles generated by fast neutrons during their interaction with liquid water. Since secondary particles spectra were used instead of simulating the interaction of neutrons explicitly, this method reduced the computation time dramatically. Double strand break induction was used as the endpoint for the estimation of fast neutrons relative biological effectiveness (RBE).60Co γ -rays were used as the reference radiation quality. The model succeeded in reproducing the behavior of the RBE and the position of RBEmax as a function of the incident neutron energy between 0.1 MeV to 2 MeV.