Study of hadron beam fragmentation with the FOOT experiment.

Particle therapy uses protons and heavy ions for the treatment of deep-seated solid tumours, but the biological damage due to beam-induced tissue fragmentation is still an open issue: effects linked to target fragmentation are hard to evaluate and neglected in clinical practice. The FOOT experiment measures nuclear fragmentation cross-sections in the 50--800 MeV/A beam energy range with about 5% uncertainty. Target nuclei ($^{16}O,{}^{12}C$) fragmentation induced by proton beams is studied via an inverse kinematic approach employing $^{16}O$ and $^{12}C$ beams impinging on graphite and polyethylene targets. Two complementary setups are used: the "emulsion configuration" measures the production of light charged nuclear fragments ($Z \leq 3$), while the "electronic configuration" focuses on the heavier ($Z \geq 3$) fragments. This communication will discuss the goals and status of the FOOT experiment, as well as the first cross-section fragmentation results obtained by the two experimental setups with 200 MeV/A and 400 MeV/A${}^{16}O$ beam on C, $C_{2}H_{4}$ and H. Accurate data on fragmentation cross-sections can be used to improve the current Relative Biological Efficiency models and the clinical treatment plans.