Comparative Study of Thermal Neutron Flux from Gold Foil Activation.

This study presents a comparative analysis between Monte Carlo simulations (MCNP-5) and experimental measurements of thermal neutron fluence using gold foil activation at the TNF2 irradiation facility of the Neutron Metrology Laboratory (LNMRI/IRD). The MCNP-5 model was constructed to replicate the irradiator geometry and source configuration. Gold foils, both bare and cadmium-covered, were irradiated and analyzed via gamma spectrometry to determine the induced activity of 198Au. The results of the calculated nuclear reaction rates were compared to the measured activities through C/E (Calculated/Experimental) analysis. The findings show consistent agreement within experimental uncertainty, supporting the accuracy of the MCNP model and reinforcing the role of TNF2 in the national and international metrological infrastructure for neutron dosimetry. Future developments will include improvements in flux mapping and personal dosimetry applications.