Fragment charge identification technique with a plastic scintillator detector using clinical carbon beams

Nuclear physics processes are an important source of uncertainty in dose calculations in particle therapy and radioprotection in space. Accurate cross section measurements are a crucial ingredient in improving the understanding of these processes. The FOOT (FragmentatiOn Of Target) experiment aims at measuring the production cross sections of fragments for energies, beams and targets that are relevant in particle therapy and radioprotection in space. An experimental apparatus composed of several sub-detectors will provide the mass, charge, velocity and energy of fragments produced in nuclear interactions in a thin target. A crucial component of the FOOT apparatus will be the ΔE-TOF detector, designed to identify the charge of the fragments using plastic scintillators to measure the energy deposited and the time of flight with respect to a start counter. In this work, we present a charge reconstruction procedure of produced fragments at particle therapy energies. We validate it by measuring the charges of various fragments at an angle of 3.2°and 8.3°with respect the beam-axis, using a small-scale detector and clinical beams of carbon ions at the CNAO oncology center. Experimental results agree well with FLUKA Monte Carlo simulations.