Differential cross section measurements for hadron therapy: 50 MeV/nucleon12C reactions on H, C, O, Al, andnatTi targets

During a carbon therapy treatment, the beam undergoes inelastic nuclear reactions leading to the production of secondary fragments. These nuclear interactions tend to delocate a part of the dose into healthy tissues and create a mixed radiation field. In order to accurately estimate the dose deposited into the tissues, the production rate of these fragments all along the beam path have to be taken into account. But the double differential carbon fragmentation cross sections are not well known in the energy range needed for a treatment (up to 400 MeV/nucleon). Therefore, a series of experiments aiming to measure the double differential fragmentation cross sections of carbon on thin targets of medical interest has been started by our collaboration. In March 2015 we performed an experiment to study the fragmentation of a 50 MeV/nucleon C-12 beam on thin targets at GANIL. During this experiment, energy and angular cross-section distributions on H, C, O, Al, and(nat)Ti have been measured. The experimental set-up will be detailed as well as the systematic error study and all the experimental results will be presented.