17–22 May 2026
C.I.D
Europe/Zurich timezone

Neutron Transport and Moderator Performance Analysis in the NEAR Station of CERN n_TOF Facility

WEP6125
20 May 2026, 16:00
2h
C.I.D

C.I.D

Deauville, France
Board: Wednesday roquefort: RD15
Poster Presentation MC6.T18: Instrumentation: Radiation Monitoring and Safety Poster session

Speaker

Gediminas Stankunas (Lithuanian Energy Institute)

Description

This work presents detailed neutronics simulations of the NEAR station at the CERN n_TOF facility, aimed at characterizing neutron spectra and activation responses for different irradiation configurations. The analysis was performed using the MCNP Monte Carlo transport code with the FENDL-3.2 nuclear data library, ensuring reliable modelling across the broad neutron-energy range delivered at NEAR. Three irradiation positions within the station were selected for spectral evaluation, and three moderator materials—LiF, Al₂O₃, and TiF₃—were investigated to assess their influence on neutron field shaping and experimental flexibility.
To complement the transport calculations, activation and inventory analyses were carried out using the FISPACT-II code with the TENDL-2017 library. This enabled prediction of isotope production, specific activity, and decay-heat evolution for materials exposed in each moderator configuration.
The calculated neutron spectra show clear differences between moderator types, demonstrating the capability of NEAR to provide tailored spectral conditions for material testing and activation studies. The activation results further quantify the radiological behaviour of samples under realistic irradiation scenarios. The combined MCNP and FISPACT-II analysis provides a consistent methodology for characterizing NEAR irradiation conditions and contributes to the optimisation of future experimental campaigns.

Paper status No proceeding file submitted.

Author

Gediminas Stankunas (Lithuanian Energy Institute)

Co-authors

Ms Simona Breidokaite (Lithuanian Energy Institute) Benjaminas Togobickij (Lithuanian Energy Institute)

Presentation materials

There are no materials yet.