Optimization of the Neutron Flux and Energy of the EFDA d-Li Intense Neutron Source

By using the d-Li stripping reaction, EFDA intense neutron source offers enough neutron flux and test volume far the study of the behavior of the materials of the fusion reactor first wall, under 14 MeV neutron irradiation, by the simulation during 1 year, of 10 years of full reactor operation life. Therefore materials specimen can be irradiated far studying their behavior, but the d-Li stripping reaction gives neutrons with average 14 MeV energy, with important energy tails (46% of the neutrons with energy aver 15 MeV, 26 % over 20 MeV), against the real fusion reactor neutron energy value of 14 MeV. The firstinvestigation in this report demonstrates the possibility to put back the energy of the irradiating neutrons at 14 MeV by neutron interactions with combination of particular materials, just defined and studied in ENEA far the project of the Accelerator Driven System (ADS) nuclear reactor. As preliminary result the average neutron energy value remains circa 14 MeV, but the presence of energy tails is compressed in 20% 01 the neutrons with an energy aver 15 MeV by the same neutron flux.