An Intra-comparison between Geant4-dna and a Variety of Monte Carlo Codes 2

20 Modelling the radio-induced effects in biological medium requires accurate physics models to 21 describe in detail the main physical interactions induced by all the charged particles present in 22 the irradiated medium (secondary as well as primary ones). These interactions include 23 inelastic events like ionization and excitation processes as well as elastic scattering, the latter 24 being the most important process in the low-energy regime. To check the accuracy of the 25 2 theoretical models recently implemented into the Geant4 toolkit for modelling the electron 26 slowing-down in liquid water, the simulation of electron Dose Point Kernels remains the 27 preferential test. In this work, normalized radial profiles of deposited energy at a distance 28 from emissions point sources are then computed in liquid water by using the very low energy 29 " Geant4-DNA " physics processes available in the Geant4 toolkit. We here report an extensive 30 comparison with profiles obtained by a large selection of existing and well-documented 31