Neutronic assessment of the IFMIF-DONES HFTM specimen stack distribution

IFMIF-DONES (International Fusion Materials Irradiation Facility- DEMO Oriented NEutron Source) is a neutron irradiation facility designed to collect data on material irradiation for the construction of demonstration fusion power plants.
This study focuses in investigate the effect of a realistic model of specimens being irradiated in HFTM in IFMIF-DONES, and its comparison with previous results with the homogeneous model. Neutron fluence rate, damage dose rates, and gas production have been calculated for the standard 20 × 5 cm² profile and a 10 × 5 cm² beam size. These calculations were performed for a deuteron beam with an energy of 40 MeV and a current of 125 mA. More realistic neutronics model gives very consistent DPA volumes with the previous. The main difference is a neutron slight streaming in the detailed one. The distribution of DPA shows irregular patterns depending on specimen location. This research highlights the significant role played by specimen distribution in enhancing the accuracy and reliability of dpa measurements within the IFMIF-DONES facility and the influence of the beam size.