Developments of the nuclear reaction and fragmentation models in FLUKA for ion collisions at therapeutic energies

Protons and carbon ions have been used for decades in several institutes worldwide for cancer treatments. The treatment planning systems rely on accurate modeling of the nuclear reaction and fragmentation processes that occur inside the patient's tissues. The accuracy of FLUKA in the field of proton and carbon ion therapy has been extensively validated. Helium ions are considered as a viable alternative to protons and carbon ions as they are featured by intermediate physical and biological properties. However, as the interest on helium ions is growing again only recently, and therefore some refinements on the FLUKA physics models for helium ions are still needed, prior to the deployment of FLUKA for helium ion therapy. In this work, nuclear reactions of primary helium ions were investigated in the therapeutic energy range and in elements of interest for hadron therapy (carbon and oxygen). Based on recent experimental measurements performed at the Heidelberg Ion-Beam Therapy center by the Space Radiation physics subgroup of the Biophysics Department at GSI (Germany), the nuclear reaction cross section models implemented in FLUKA were refined. This allowed the achievement of more accurate dose calculations.