Pre-analysis of the copper neutronics benchmark experiment for nuclear data validation

Abstract A new benchmark experiment on pure copper assembly is presently underway at the Frascati Neutron Generator (FNG) aimed at testing and validating the recent nuclear data libraries for fusion applications under 14 MeV neutrons irradiation. The Copper block has been designed on the basis of the pre-analysis presented in this work, performed with the MCNP5 Monte Carlo code, using JEFF 3.1.1 nuclear data library for transport and IRDF2002 for activation foils reaction rates. The pre-analysis has been performed in order to define suitable dimensions of the copper block and to optimize the experimental set-up for the measurements. This includes the definition of the detectors positions and the irradiation conditions required to get measurable activities for the activation foils. Furthermore, the design has been optimized to reduce the effect of the background due to the neutrons back-scattered from the FNG bunker walls. A 60 cm × 70 cm × 60 cm copper block, without any shield, results suitable for conducting a “clean” benchmark experiment.