Speaker
Description
The neutron time-of-flight facility (n_TOF) at CERN, in operation since 2001, is a pulsed spallation neutron source designed for precision measurements of neutron-induced reactions. In the n-TOF facility, neutrons can be generated in an energy range from the meV up to GeV, enabling experiments in astrophysics, advanced nuclear technologies, and medical applications. There are three experimental areas: EAR1, EAR2, and NEAR (n_TOF Experimental Area for Radionuclide studies).
A third irradiation area is located only a few meters from the spallation target. The area is divided into two distinct zones: i-NEAR and a-NEAR. The first one is located within the shielding and is used for the material degradation calculations under extreme radiation conditions, where doses can reach up to MGy per year. The second one is positioned outside the shielding, where a collimated neutron beamline delivers neutrons to an accessible irradiation hall. These areas provide a versatile environment for testing materials, performing activation analyses, and assessing radiation hardness under controlled and well-characterized neutron fields.
This work presents transport simulations of the NEAR station, performed using the Monte Carlo N-Particle transport code MCNP6 with the FENDL nuclear data library. That ensures accurate representation of neutron interactions across the wide energy spectrum delivered at n_TOF. In the NEAR station, 3 irradiation positions were selected for neutron spectra calculations. Additionally, 2 moderator materials: Be and Al₂O₃, were selected. To complement the transport calculations, activation and inventory assessments were performed using the FISPACT_II code with TENDL nuclear data library.
The combined use of these codes enables the prediction of isotope production, specific activity, and decay heat values in irradiated samples. The calculated neutron spectra for different moderator setups show that the NEAR station can be adjusted to provide the spectral conditions needed for different experiments. In addition, the activation calculations give quantitative information about how materials behave under irradiation. Overall, these results provide a reliable approach for planning and understanding irradiation experiments at NEAR, as well as for testing nuclear data in high-flux neutron fields.
| Type of contribution | Poster |
|---|