Speaker
Description
Understanding nuclear fragmentation reactions of light nuclei (A < 20) in the 100–800 MeV/u energy range represents a key challenge in applied physics. A detailed knowledge of these processes could provide crucial insights for optimizing treatment planning in Particle Therapy and for assessing radiation exposure risks in long-duration human spaceflight. Despite the relevance, experimental databases are still scarcely populated with the corresponding data, forcing to mostly rely on phenomenological descriptions to model nuclear fragmentation reactions. As a consequence, the Monte Carlo codes employed for radiation risk estimation in both Particle Therapy and space radiation shielding carry substantial uncertainties.
The FOOT (FragmentatiOn Of Target) experiment has been conceived to address this gap by conducting a comprehensive campaign of high-precision nuclear fragmentation cross section measurements. The experiment uses light ion beams — from $^1$H to $^{20}$Ne — at energies spanning 100 to 800 MeV/u directed onto targets whose chemical composition mimics human tissue and spacecraft shielding materials. Designed as a fixed-target experiment, FOOT is capable of detecting, tracking and identifying both the primary beam and the resulting nuclear fragments, while fully reconstructing their kinematic properties. This is achieved through a redundant detection strategy that allows measurements to be performed in both direct and inverse kinematics. The final goal is the measurement of double differential cross sections in kinetic energy and emission angle, with maximum uncertainties of 5% and 10% for projectile and target fragmentation, respectively. To accommodate the variety of ion beam facilities where data will be collected, FOOT comprises two portable, complementary setups: an Emulsion Cloud Chamber with wide angular acceptance, optimized for light fragments (Z ≤ 3), and an electronic detector system with narrower angular acceptance suited to heavier ions (3 ≤ Z ≤ 8), incorporating a magnetic spectrometer, a Time-Of-Flight system and a calorimeter.
The FOOT Collaboration has completed the assembly of both setups and has already performed a set of physics data taking. An extensive commissioning phase was carried out to assess performance at the level of individual detectors and full event reconstruction. Both setups have demonstrated highly encouraging results in fragment tracking and ion charge identification, meeting the design requirements of the experiment. In parallel, detailed studies of systematic uncertainties in the event reconstruction pipeline have been conducted on Monte Carlo simulations, leading to the first experimental measurement of the differential fragmentation cross sections of $^{16}$O on C and C$_2$H$_4$ targets. This contribution presents an overview of the FOOT experiment, covering its scientific program, the current status and its planned future developments.