## 2 Overview of the ELIMAIA Beam Line
The beam transport elements, as it has been established in the signed contract, will be characterized and tested using conventional accelerated and laser-driven ion beams. An experimental hall at the INFN-LNS has been entirely dedicated to the ELIMED project in order to perform all the tests required for the ELIMED beam line using proton beams delivered by the Tandem and by the Superconducting Cyclotron (CS) (LNS, Catania, Italy). After the main beam transport elements, diagnostics elements specifically optimized to measure the beam emittance for laser-driven ions will be used for the on-line characterization of the collected beam. Complementary diagnostics systems such as Silicon Carbide (SiC), Diamond or Secondary Emission Monitor (SEM) detectors will be provided. This detector will be used in Time of Flight (ToF) configuration, providing a spectral analysis of the accelerated and transported ions. A precise knowledge of the absolute dose, delivered by the incoming radiation, is crucial in several applications, as for instance the hadrontherapy ones, where the dosimetric accuracy is a key prerequisite. Indeed, for clinical accelerator-driven proton beams, the dose uncertainties at a reference depth in water with calibrated plane-parallel ionization chambers are 2.3%, according to the Code of Practice for Dosimetry IAEA TRS-398 of 2006. Nevertheless, the pulse properties of laser-driven ion beams differ significantly from those commonly provided by medical accelerators in pulse duration, peak current and correspondingly pulse dose rate and energy spectrum. Thus, detectors must be dose-rate independent allowing measuring very intense and short pulses without suffering from saturation effects and guarantying the required accuracy also for high intense beam pulse. Furthermore, it is mandatory to develop on-line beam monitoring and relative dosimetry systems, suitable to operate with high intense beam pulse and strong electromagnetic noise, ensuring a negligible beam perturbation. In order to fulfill all the requirements new detection devices and techniques must be designed and developed. The solution proposed to perform relative and absolute dose measurements implies different alternative approaches,as for instance SEM detectors [18], CR39 solid-state track detectors [19], Gafchromic films [20], transmission ionization chamber for high intense beams [21] and Faraday Cups (FC) [22]. Figure 1 shows a schematic layout of the ELIMED beam line where the elements composing the three different sections are clearly visible in their preliminary design. Monte Carlo (MC) simulations will play a key role for the realization of the ELIMED beam line transport elements and for the development of the detectors. Indeed, MC results allow accurate designing of some key elements, particularly for the in-air section of the beam line, and to predict the particle transport, as well as the fluence and dose at given points of interest. Moreover, radioprotection studies can be carried out in order to design appropriate shielding solutions. For the simulation of ELIMED beam line the MC toolkit GEANT4 (GEometry ANd Tracking) [23] will be used. GEANT4 is one of the most versatile and widespread codes used today for particle tracking, as well as being widely used for different physical applications. It is a C++ object oriented toolkit allowing the simulation of particle interactions with matter. It provides advanced functionalities for all the typical domains of detector simulation: geometry and material modelling, description of particle properties, physical processes, tracking events and run management, user interface and visualization. Initially developed for High Energy Physics experiments (HEP) simulation, GEANT4 is now widely used also for multidisciplinary applications and, in particular, medical physics. It allows the tracking of any charged and uncharged particle relevant for radio diagnostics and radiation therapy.