Abstract ID: 173 Geant4-based Monte Carlo simulations of a transport beam line for multidisciplinary applications of laser-driven proton beams

The ELIMED (MEDical and multidisciplinary application at ELI-Beamlines) beamline is being developed with the aim of transport and select in energy proton and ion beams accelerated by laser-matter interaction at ELI-Beamlines (Extreme Light Infrastructure) user facility in the Czech Republic [1] . The beamline will be a key part of the ELIMAIA (ELI Multidisciplinary Application of laser-Ion Acceleration) user beamline, where experiments will be carried out with the purpose of investigating the feasibility of using laser-driven beams for multidisciplinary applications, including medical ones [2] . A Monte Carlo simulation of the ELIMED beamline has been developed for the following purposes: to support the design of the beamline in terms of particle transport efficiency, to optimize the beam parameters at the irradiation point in air and, finally, to predict the transport elements parameters to deliver dose distributions of possible clinical relevance [3] . The application has been developed with the Geant4 Monte Carlo toolkit. It has been designed in a modular way in order to easily switch on/off geometrical components according to different experimental setups. The application has been preliminary validated comparing particle tracks to results obtained with reference codes for transport of particles in magnetic fields, with a good agreement. Specifically, energy distributions, lateral beam profiles and longitudinal dose distributions in the in-air final section were simulated for proton beams with energies ranging between 5 and 60 MeV. A transmission efficiency of more than 10% was calculated at 60 MeV, which implies the delivery of up to tens of cGy per pulse at the sample irradiation point. Assuming a repetition rate of 1 Hz, between 1 and 10 Gy/min can be potentially achieved in such conditions. These results are of great importance to assess the possibility of carrying out in vitro and in vivo radiobiology experiments aiming to demonstrate the possible future use of optically accelerated beams for therapeutic purposes.