Characterization of the irradiation parameters in the IFMIF high flux test region

The purpose of the international fusion materials irradiation facility (IFMIF) is to provide typical D-T fusion irradiation conditions for future material testing and material development. In order to demonstrate the suitability of IFMIF for irradiation experiments a comprehensive characterization of the neutronics of the high flux test region (HFTR) has been carried out. For Fe, the neutron flux density was found to range between 4 x 1014 and 1015 n/s cm2 which corresponds to 20-55 DPA/FPY in a maximum volume of 550 ± 180 cm3. Gas production rates were calculated and a H/DPA ratio of 35-50 appm/DPA and a He/DPA ratio of 10-12 appm/DPA were found, which are very similar to those of a DEMO D-T fusion reactor. Additionally, an analysis of the primary knock-on spectra has been performed and a displacement damage characteristic in IFMIF almost ideal to the first wall of DEMO was found. IFMIF therefore provides an adequate environment for the simulation of D-T fusion reactor irradiation conditions. (orig.)